"The check is in the mail"

The Gray Zone exists for all relationships, whether business or personal, romantic or platonic. There is a process of discovery involved in getting to know people, getting to know if you like them, if they have what you need, what their goals are for the relationship, etc.

This is true even if both parties are good people with similar values, etc. There can be unpleasant surprises that are dealbreakers even if both parties mean well, try hard, are honest and so forth.
A cat that sits on a hot stove once will never do it again. It will also never sit on a cold stove again.
The standard of "assume good faith" only works when you lack adequate knowledge to determine if it is a good faith effort or not. If you continue to assume good faith after it has become clear there is a pattern of lies and abuse by this person, you are being a fool and they are probably actively encouraging that.

You can only reasonably give the benefit of the doubt when there is doubt.

The problem is abusive people know that good people tend to give the benefit of the doubt and will seek to intentionally instill doubts. This can throw sand in the gears and make it hard to figure out how best to proceed.

What people want from a relationship can change over time. People who started out as FWB may decide they want something more serious because THIS is working so well, it seems like it has what it takes to be love and marriage.

That may not be true. It may only work this well because it is FWB and the whole thing will fall apart if you change the deal, but the reality is most relationships start as "dating" and gradually become more serious over time. It's not generally standard practice to just up and marry someone you just met.

The fact that feelings change over time and you can expect that -- in fact, you are likely counting on feelings changing -- complicates the question of how to navigate a relationship.

If you are crystal clear at all times about what you want, other people being flakey is easier to deal with. If you are looking for short-term fun, no strings attached, time to bail when they start sounding serious.
"I know it's time to go when she gets all misty-eyed and starts talking about wanting a baby."
-- Some guy in some article I once read
People conning you will generally play on your hopes and fears. If you are hoping to have a future with them, it can be difficult to clearly distinguish being conned from making plans for our future.

This goes double if you are going through a divorce, the relationship started as an illicit affair or for any number of other reasons.

I have read a bunch of research about affairs, so let's start there. Here are some basics:
  • People often know their relationship will end before that info is "public," so it's not always the case that an individual in a relationship who chats you up is looking for an affair.
  • Contrary to common views, affairs rarely are the cause of the relationship ending. It is much more common for someone to decide they want out and seek out an affair to help them cope with the transition.
  • Contrary to how people having illicit affairs tend to FEEL about it, it's extremely rare for this to lead to happily ever after. In MOST cases, the marriage or serious, long-term relationship ends and the dish on the side gets dumped within about a year.
I have come to think that it's just hard to establish a relationship with happily ever after potential and a lot of the above issues aren't really peculiar to affairs per se. Romantic comedies pretty routinely have some "secret" that gets divulged that it was completely reasonable to not tell the person earlier and wasn't some skeevy move at the time but became a problem later because they got involved or got more serious about each other.

I have come to believe the dish on the side gets dumped because the person isn't looking for someone who can be their "everything." They are looking for someone who adds what their current relationship lacks.

The reality is no matter how a relationship begins, you can be what their life lacked at the time and it may not have a future. Once they get whatever they lacked, you may be history. It may not have long-term potential.

The big issue with affairs is people tend to feel guilty and also -- perhaps more importantly -- have trouble getting constructive feedback. If you are having an illicit affair, you probably are not going to want to cry on the shoulder of your mom or best friend about your fears and insecurities to get a reality check from someone you trust who has some hope of being more objective than you.

Again, there can be other reasons you can't get that kind of support. Maybe you come from an abusive family and don't trust any of your relatives to give you good feedback. Maybe your parents are already dead. Etc.

The way you avoid getting strung along indefinitely by someone using you and conning you is a multi-step process.

First, you need to be honest with yourself in a way some people are not. Honest about what you actually want here, what's realistic to expect in life given x, y and z, and also honest about what YOU have to offer. Don't become the person running a con job, even inadvertently by politely "agreeing" with what they are projecting onto you.

During my divorce, I had a couple of boyfriends and eventually concluded that I was unintentionally stringing people along because I really was not in a position to commit. Politely going along with what men wanted to see in me and HOPING it would line up that way and work out was proving to be unrealistic, so I had to get more aggressive about letting people know that I'm not what you want to see in me. That's just not real.

Step two, assess current value. Keep it real and what's REAL is what the relationship is doing for you TODAY, not what you HOPE it MIGHT become -- SOMEDAY.

If you DO find yourself having an illicit affair -- which I don't recommend doing -- or even dating someone in the process of divorcing whose divorce is not yet final, I will suggest you REFUSE to agree to be "faithful" to them while they sleep with their spouse and string you along. I recommend you let them know that you are not their property and if they want fidelity from you, they need to be able to give you the same -- not PROMISE to SOMEDAY.

If it's not something they can give you TODAY in the here and now, don't let them make demands for that from you.

If only for germ control reasons, I don't actually recommend you sleep around casually. That's not really my cup of tea generally, so me saying "don't agree to that" is not me saying "Make sure you also sleep with someone else!"

What I am trying to tell you is to remind them politely "That's not a reasonable expectation and IF I meet someone and WANT to date them, I CAN. You don't own me."

If you agree to be faithful before they can offer the same, you are setting yourself up for an abusive relationship where they will feel entitled to a relationship where the rules for you amount to servitude to them and the rules for them are somehow "different" for some damn reason and good luck walking that back once you start down that road. Best practice: Nip it in the bud, even if it means you need to tell this one "Bye!"

If you are having an illicit affair, agreeing to be faithful to them while they take their sweet time getting around to leaving their marriage means this will likely drag out for a LONG time, possibly YEARS. They have no reason to jump on it if you will patiently wait by the phone and not get on with your life without them while they dick around.

Step Three: Reassess periodically.

If you are in some relationship limbo, such as having an illicit affair HOPING they will leave their spouse for you, and it has gone on for some time -- possibly YEARS -- don't just assume that the only way this changes is "When they leave their marriage and finally marry me." Don't just stay out of habit.

If you find yourself growing increasingly unhappy or if something important changes in either your life or theirs, rethink your reasons for accepting this relationship under these circumstances. Go back to step one and go over your reasons for being here to begin with and see if they still apply.

During my divorce, I was acquainted with a man who seemed interested and I sort of hoped it might go somewhere and this situation dragged out a LONG time. He likely imagined he was super important or special or very, very attractive to me but it was really situational.

This could have ended up being a big problem for ME if I had been thinking about it in terms of "the length of time I sort of hoped this might go somewhere means this guy is all SPECIAL." Fortunately, I don't think that way and was able to readily let it go when circumstances changed.

It ended up being a thought experiment for me which helped me go "Gee, I thought men with X trait/situation were what I should be looking for and THIS went NOWHERE. So time to get over that idea." That was a positive development for me and relatively low cost given that it never involved actually dating at all.

Especially if you are having an illicit affair, ask yourself WHY you are accepting this situation. And if things in your life change such that your reasons for accepting it cease to exist, consider ending it and telling yourself you deserve better.

Last, try to reassess in a timely fashion. This generally means paying attention to milestones, not deadlines.

If you have a deadline for buying a house for some reason and you want to live with them but your SO is all "Nah, I don't want to live with you and go halfsies on this." you should probably start planning your future WITHOUT them at that point. This is a big life move and if they don't commit at that point, trying to sell it and buy a different house together later will be a huge pain in the butt, expensive, etc. so buying a house without them and not dumping them will likely bite you in the butt for years to come.

This is especially true if you are wanting kids in the future or they aren't the type to live out of a suitbag who basically can take the other half of the bed and stick a few things in your closet. If their lifestyle and current possessions need substantial space, you can likely readily predict that "If we don't buy a house together for BOTH of us, me buying what I can afford on my salary will never be big enough for both of us."

Further, you can count on them routinely being inconsiderate in a way that hugely inconveniences you for the duration of the relationship. This is not likely to be a one-off anomaly.

Failing to reassess at the time of some milestone or watershed moment seems to be the single biggest cause of people cutting their own throats. It's unfortunately common for people to not reassess until the negative consequences of that watershed moment start rearing their ugly heads and at that point it's often "too late."

So anytime something "big" happens in YOUR life or the life of your SO, take a little time to wonder how this impacts things. Even if you aren't ready to dump them yet, it will make it easier to decide what to do later when it becomes clearer where this change leads.

If you want a serious relationship -- marriage, children -- it's perfectly reasonable to talk about the future and to try to sort out what each of you needs in the here and now from the other person in order to have any hope of getting there from here. But it's shockingly common for people to make demands in the here and now for some hypothetical future value that may never materialize.

Do your best to keep it real and to make sure the relationship has actual current value for you and the relationship makes sense for you in the here and now even if those hopes and dreams never materialize. Don't live your life in some hypothetical future and make decisions based on that.

Letting people demand fidelity or whatever from you now in hopes of getting the same from them "someday" just serves to make you an easy mark.