I think you've either not been reading or read a different game and got confused.
Most of them have specifically said they are not willing to share.
Only 1 single person has said she would share and that was only with Deb and Lily and she has since changed her mind.
That's why the devs have said there will not be a harem.

Perhaps you haven’t man whored enough so you haven’t seen that dialogue Idk. I agree that the only harem ending would definitely be non canon, but plenty of the LI’s have been willing to share.
Debbie was willing to share Lily.
Lily was willing to share with Katie.
Katie did share you with Debbie and Lily, but I agree she wants you to herself now.
Jenna doesn’t care who else you are with as long as you love her. Monica is probably a deal breaker there though.

Can’t say for certain though Jenna is freaky.
Monica I still see a threesome possibility with Zarah. But definitely wouldn’t share with her daughters.
Zarah was trying to get you to fuck Monica so I doubt she’d care about anyone else.
I could go on but I’m sure everyone gets the point.
Other than Elaine I think most are willing to share. Obviously not with everyone.
I’m certain Avaron knows this and was just saying no harem possible. But I went on a rant anyway
