Alright, than how many MFF threesomes is Ian in compared to the MMF threesomes lena is in?
Ian seems to have multiple soft "bad ends" when the girls figure out he's not monogamous
Seems like you have zero idea about this game.
Threesomes only started in last chapter for real to both MCs and right now is 1 threesome for each one. And in the prologue of the next chapter Lena clearly suggest they can try a threesome to fulfill Ian's fantasy to have sex with two girls. So a FFM threesome to Ian is aready on the way.
And "bad ends" when "girls figure out he is not monagamous" is literally only Lena breakin up with him if he fuck Holly, someone she really like and she really care about. That's the only situation. Aside that, she can know he is fucking other girls (Like Alison or Cherry) and she will keep date him.
Is entirely possible make a playthrough as Ian where he fucks five different girls in a regular basis - Cherry, Emma, Lena, Minerva and Cindy - until he decide get in a serious relationship with Lena (or keep things casual with her and all others). As for Lena, the max of guys she can fuck in one playthrought if i'm not mistaken is also 5 - Robert, Mike, Ian, Jeremy and Axel - and if she did Jeremy she is blocked to start a serious relationship with Ian. And sometimes Lena has to choose between see Ian, Mike or Robert so even if she is fucking with all them, players can't get all the scenes with them together in the same playthrough.
In terms of sexual content, Ian and Lena are fairly equal. Both can have plenty of sex with different people in one playthrough. Lena can have more sex but only because we can play her as a bissexual girl, so she can have sex with both men and women while Ian is 100% straight, and i'm pretty sure player prefer him that way. Both can cheat on each other as soon they become a couple. And there is zero bad consequences for both for now
There is also a path where Ian can be really dominant towards Lena (and she love it), which is tracked and increased by the ian_dom_lena variable. If this will lead to cuckquean path or something similar we will wait and see, but considering that Lena is already willing to set up a threesome with her new boyfriend and very possible another girl, it doesn't see to far-fetched to me. Just doesn't expect a harem to Ian. This isn't and will never be a safe harem journey