Thank you for asking!
The short answer is: Yes!
Long answer: It will be up to you! You can raise your affinity with only one or every girl you like, thus having multiple "affairs/girlfriends" and a harem ending if that's what you want.
As for the sexual content, almost none of it is forced. I'll do my best always to give the player options to avoid or skip it if it's anything other than "standard" intercourse.
For example, if you talk to the Secretary (in Chapter 01 already), you'll find multiple bdsm pictures (and scenes). If that's not your thing, you can simply avoid talking to her and won't get this content. For the reasons you express, the first pictures you find of her are soft, so you know what you're getting yourself into.
Finally, skipping/avoiding sexual content or not raising affinity with a character will not prevent you from getting anything story-wise.
I will add labels to my game page as scenes are added to the game too.
I hope I answered your questions. Feel free to ask if you have more.
Thanks for checking out my game, it means a lot to me.
