I never did, now that I'm older and understand a woman's cycle better I would have kept track of her cycle and planted loads balls deep when I knew she already dropped her egg. I did have her riding me backwards, and that one had an epic ass, and she got me over the edge just as I pushed her off. She looked back in surprise to see my cock shooting streams of baby-gravy in the air. She got nervous again and started talking about condoms again after that .
Way back in the days I used to wear a rubber for sex (don't ever now - gave that up!) I had a few split midway through a heavy fuck session. You feel it go and think "oh oh" then you just keep on fucking!! And you don't pull out.
Looks pretty genuine - typical college bedding! Know that feeling - when the rubber splits: you have to make a decision - pull out and tell her what happened or keep ploughing on. Yeah? What do most of us do? Yeah - I thought so! Been there!