I had a friend in middle school who went by Cat and he was a boy. It was short for Catalin.
Stacy and Kelly can also be male names so it’s not that far fetched. Nor is the timing between the posts. If you have Facebook open you get notified as soon as someone posts a comment. The last comment from Kat could easily have been typed within a minute.
If Court and Kat are identical twins, then it’s not cheating. … Also, Court sounds like it’s short for Courtney, and I have never met a dude called Kat. Sounds like some lesbian sisters’ girlfriend swapping. … And let’s face it, that’s kind of hot.