Obviously live in the States, but…
When people find out I’m a City fan (clothing, car plate, or them asking me where I’m from and if that means I’m a United fan, which gets a fake spit on the ground) and take pleasure in telling me they’re a United fan!
I always tell them “Of course you are, because you’re a foreigner! I’m from Manchester, where most City fans come from, not overseas where United fans suddenly became United fans because they were the big team when the Premier League was created for satellite and cable football to be broadcast worldwide!”
If they take it in good spirits, we can have a laugh from there, but if they start in on ANYTHING about City post-Mansour, I simply ask them to name a current starting line up for United! No-one can do it and has never failed, and always allows me the “Oh yeah, I can see you’re a BIG fan!!!”
That usually boils a bit of foreign piss!!