alright, so i having sex with this girl, missionary position. the thing is, she isn't flat on her back, she's kinda propped up on a pillow or two. now, the problem is that i push forwards with my pelvis to do the 'in' motion but my dick doesn't really move in.. so like, the actually intercourse just kinda died since i clearly failed at it. the thing is, this is the first time it's happend, i didn't know what the hell was wrong. anyone have any ideas of what went wrong?