>>395037
Hey OP, I am exactly the kind of guy you talk about. I am 20-ish, bi and kinda in the closet about it- yadda yadda. As I had some success with traps/cuteboys/twinks, I'll chime in here so you get a picture of the other side for what its worth.
As others have pointed out, a lot of it is down to mindset. I'll give you an example - in this case mine. I always was at least curious about other boys and had some stories with other boys in my past, but nothing serious for one reason or the other. So I often found myself wondering "what would XYZ be like with a boy". Next there is the part about being feminine - and Ill be harsh, feminine men have to deal with a similar clock as women in that regard. Their "attractive" feminine-trades will eventually fade.
Now picture this mindset being imprinted in your brain and then you stumble across posts like 19/m/cockslave/living 10 minutes away - wanting to suck dick - of course this will make you wonder. Especially if there is a pornographic image attached.
Lets say you have some form of contact - what is gonna stop you from texting. Nobody apart from you and them will know. In your head you'll see it like an easy way to answer your own questions.
But at the same time I dont want to step out of the closet as bi - because imo there is still this huge social label that says "this guy is attracted to other guys", even if I am also attracted to women. Its a label thats gonna stick to you. And if you dont have the confidence in yourself to deal with it, there will almost certainly be the thought: "what if I dont like it and I'll have this label stuck to myself". And many guys (me included) are scared shitless of that. insert joke about fragile masculinity here
Sadly, this hurts/kills initial potential for a long term romantic relationship as they are built on confidence and openness and that is why you will have a lot if approaches like the ones you mentioned. Apart from being unfaithful, thats just flat out disgusting and unfair to me.
Now my two-cents on your last question. It is absolutely possible to still find a partner/relationship, as imho men are so much easier to filter through in that regard compared to women. And if you find a guy with similar interests thats nearby, that is attractive and open about what he wants and what not - whats gonna stop you from having a good time?
2 years ago I had an amazing f+ kinda arrangement where I was always open about my intentions and where we would stay in contact via text/phone and meet to talk/play/cuddle/fuck every second week or so. We both got to fulfill urges we had (being vulnerable, sex, even activities). At the same time I kept urging him to keep looking for a romantic relationship as I didnt fit into that role. He eventually met someone, we talked and thinks were fine. And the 4 months we shared like this were so much more fulfilling than being single and relying on the very next opportunity around the corner, as we reassured each other in a way.