We saw Trish approach Karen, but what if she also approached Foggy at some point. He is 100% her type and they were both in a tense but also boring situation. Maybe they diffused it with sex?

Up to the author whether Foggy is in an open relationship with Marci or feels bad about cheating on her as part of it.

Bonus if there is follow up where Trish comforts him when Matt didn't come through that door.