Wow, this was a controversial end to the season lol. To be honest I am also not a fan of the "forced kiss until the girl submits" trope, but strangely enough, given the context of their relationship, I'm not condemning what ML did. I'm not condoning it either, but the guy is frustrated over FL's guard being fully up despite everything he has done (he knows FL has feelings for him from eavesdropping), plus with the added stress of hearing his love rival talking with her right after that incident. She has been giving him conflicting signals from the very beginning despite having feelings for him. If she really didn't like him that way, she should've rejected him outright.
The thing I hate about the forced kiss trope is when the girl "magically" gets feelings for the guy because of the kiss. In this instance, that wasn't the case. I don't think it's rapey but it was forceful and desperate.