See, it happened again...you just didn't get it. Every girl, every time, by the time you finish inside them they've turned into a raccoon. They never covered this back in sex ed class, but then, there was plenty of other stuff they didn't cover either, so maybe this is just a thing that happens. Is it a girl thing, do most girls just do this as part of reaching climax, or is it a "you" thing? A couple of them have yelled at you afterward, blaming you for what happened, but you weren't sure it was your fault. You didn't do anything in particular, it's not like you're a wizard. This is just how every encounter ends up. Really, further research is required. You're gonna get to the bottom of this, no matter how many girls it takes.