They are all crazy and if they say "I do" they will be miserable.
Milton thinks he is level headed and is making a rational decision but it doesn't work like that. Love is not math. Marriage is not math. And he is about to marry the least "math" or logical person in the whole show. She treats him like a child all the time, they can't even have dinner without her giving out about his juvenile tendencies.
I used to be in a "loving" and "good" relationship and waking up "cranky". I thought this is how I was normally. No way. You should wake up and be happy, rested. Waking up cranky is not normal and it is a major red flag for me now. They are both miserable already.
Stacey is a witch. She expects him to show her love all the time, do things for her all the time. That argument was super crazy. She really came off like a superficial person. He bought her flowers every Monday and he is way more into her than she is him. They do thrive in being toxic together, hence ganging up on Johnnie. It actually does turn him on because it's the only thing he gets excitement from in this relationship.