How to handle "dramatic" friends?

When I mean “dramatic” here’s what I mean (not sure what the word is)

Let’s say, I have a friend named *Michael that is friends with *Stacy. Stacy and I used to be close friends until I distanced myself because she let me down too often. An anquaintance says, “Oh, I love Stacy!” and Michael says, “Me too!” but gestures a look at me that suggests my silence has a purpose and says, “I’m not saying anything about that.” I don’t want to bring up the fall out Stacy and I had because that’s my business and past, I don’t want to spread that I have anything against her. However, I just kept silent and moved on.

Another example is that there is another girl I don’t associate myself with just for my own personal morals. I don’t know her, I don’t have anything against her personally, but I’m not going to go out of my way to be friends with her. Michael says to a friend, “OH, only girls say bad things about her. Everyone else is jealous.”

Another thing, I told him my thoughts about this girl that he’s crazy about. Said she doesn’t seem to be that into him, but he keeps saying we’re all wrong and he’s gonna prove me wrong. So I’m wondering to myself, “Why even ask my opinion?”

Small things like this irritate me. How do I talk to him about it? Or am I overreacting?