Pretty sure Elsa is a lady dev.
If i remember correctly Elsa asked in the main game's thread a long time for people's thoughts on other guys interacting with the girls, always in non-sexual ways, while being nude and the overall conscience was that it was preferred to not happen at all, but if it does then as long as it remains 100% non-sexual it wouldn't be a big deal.
I haven't played this yet, because Olivia isn't my favorite girl, and I'm a few updates behind on Nudist College (the last time I played it was still Nudist School), but unless something major has changed then I'm pretty sure there will never been any other guys doing anything sexual with the girls at all, and even the girls aren't going to be doing stuff together either.
Anyone can correct me if my information is out of date but I doubt
Elsa94 would torpedo her games for some random one off images.