Yes, you can definitely feel it.but it's a sometimes thing ! you feel his penis become very hard and then comes the throbbing, pumping feeling, and the head gets very rigid, and then you feel the warm ejaculate inside of you.
yes I can feel it whether or not he's wearing a condom. I find that his last thrusts become slightly more intense as it pushes against my g-spot - most of the time it triggers a climax in me too. This is just vaginal sex though, I can't fee it when he comes in my butt .
I describe it as a "tightening of his cock" rubbing against me.