I am pretty sure, Mizuki and Mao won’t end up kissing..
Here is my prediction,
“ It’ll be a case of a classic too drunk for anything to happen.. Mao will make a move, Mizuki will profess her love for Hinata. Mao gets rejected.. Mao will pretend that she doesn’t remember anything from last night but she clearly remembers the rejection.. Mao will exit the story but Hazuki either a) Finds out about Mizuki’s affair with Hinata and that leads to the next arc or b) gets more clues about Mizuki’s affairs”..
However if the Author does make Mao to kiss Mizuki, then it’ll be a treat!! Mizuki is already cheating on her husband, what’s one more?