Haha seriously..? That is such a bizarre thing to get upset about.. to be that OCD about the MCs harem smooching each other. I feel like it speaks to some real life hangups, like people being mad that LIs have had past relationships and aren't all virgins.
The fact now even two women kissing each other can be remotely seen as ntr stuff is mind boggling to me. To try and humor the .05% of people weirded out by that is a fools errand.