I answered this question privately for a friend via email this morning, but thought it may be relevant here as well:
“What’s with those porn clips where it’s like a fake dick cumming gallons of jizz on a girl? I mean, like is that a thing people are into?”
There’s a part in “Sex at Dawn” that talks about sperm competition.
The theory is that humans are naturally more like Bonobos than
Gibbons, so the biological idea is more to drown other dude’s sperm
with your own than it is to convince your partner to be monogamous.
Therefore, a man seeing women have sex with other men is a turn on.
Also, seeing HUGE amounts of sperm would be the heightened version of
a sperm competition trigger, just as those 48WWW sized ladies with
novelty chests are the heightened versions of natural attraction to
the female breast as a fertility indicator.
So yes. That is a thing that some people are into.
P.S. As always, if you *are* a scientist and have corrections or extra light to shed on the matter, please feel free to let me know.