I (30F) have been friends with a girl, let’s call her Zee (27F), for about a year and a half. She’s not really into art, but she enjoys going to exhibitions to take photos. She likes to play pretend as if she’s an ig model, even though her account is private, and since I do like art, I sometimes tag along and help her take pictures for her ig. My sister is an artist and will be showcasing her work in an upcoming exhibition, so I invited Zee. She said she’ll come, and also mentioned bringing her friend, let’s call him Po (30M), so I can finally meet him. Here’s the issue: Po is a work friend she’s known for about six months. He’s married, has a 3 month old baby, and he cheats on his wife frequently. While he hasn’t "cheated" with Zee, he does flirt with her, and his wife doesn’t know about their friendship. I told Zee he’s not a good man and that she should keep her distance and that it’s unfair to his wife, but she insists that his choices are his responsibility. As long as she isn’t directly doing anything wrong, she says she doesn’t care if he chooses to hide their platonic friendship from his wife. My biggest concern is that if she brings him, he could meet my family (I still live with them). My father is very conservative and already uncomfortable with male-female friendships. He might give me hard time about Zee having a male friend but that's manageable. But learning that her friend is a married man would be a serious problem. I fear this could escalate into something that might actually threaten my safety at home. So what do you think I should do? And am I an asshole for thinking of asking her to either not bring him or align with me to make sure when they come my dad won't be there?!