Yes, it feels different... At my age I seldom get really hard, but I still enjoy cumming just as much as when I was younger. You know that you're very lucky that Miss C has such a great curiosity and has so much fun experimenting!
Your semi is bigger than my full hard-on! Still, it's an enormous turn-on for me to know that Miss C is also interested in cocks that aren't so hard -you know why! 😏 Does she also know that it's possible to make a cock cum without it getting hard at all? You have to be quick and determined, and it's never the best of orgasms, but once in a blue moon it's fun to do, almost like rubbing a clit...