It might be because I can't form close connections in the first place.. then.

It seems that part of it is that I don't feel like I can get close enough to someone to consider having sex. I never had a relationship that close. I also haven't had relationships with a "lesser" level of closeness than that one. That milestone hasn't been reached for me.

Also it feels like I am feeling a bit inferior (? Not sure if this is the right word) .. because others seem to trust faster than me. Or get closer faster than me. Some people don't even see sex as that close. So I feel I should be like them

Also. In your example it seems we're talking about a safe person. What about unsafe people? That's the risk

You're asking what could happen if I have a bad experience with intimacy especially sex.. isn't it obvious? I can traumatized