I've noticed with extra girth or when the girl is tighter, my penis conforms to the smaller size after fucking for a minute or two. However, getting it in feels AMAZING, and if you have a cock ring, it can't conform so you stay huge. But none of the girls I fuck will let me wear a cock ring because I already leave them super sore without one. I need to get a new cock ring since I've grown out of my old one, then I can feel the super tightness the whole time I'm fucking(or at least as long as she can stand it)