Hi. My partner and I are in our 40s. I've only had sex with my fiance so I don't have a lot of context. I've never been able to come from sex. We do extensive foreplay and she's very wet when we start. When I first put my penis in everything's great, I'm moving in and out and after about 3-4 strokes something in her body changes and I can't move any more. It doesn't feel like she's super tight. There isn't a wall that I can't get past. If I try really hard to move in and out I usually fall out. This can't be what it's like for other people or nobody would get pregnant. We tried legs together missionary and I popped out so many times that we had to give up.
The reason we've never really discussed it in depth ("i wish you could come too" is about as far as it goes) is because I have elevated prolactin and erectile dysfunction as a result. It's being treated with medication. Also, she's had other sexual partners (last one a decade ago) and they were able to get her pregnant so I know it worked. So we basically blamed the problem on my issues. But I'm plenty hard enough during sex, even though i get a little deflated after a few minutes of grinding with no stimulation.
I'm a little scared to try other positions because i've never been able to insert my penis, I just can't tell when it's in.