Fan Bashing?

I live in a state where we have two baseball teams. It's pretty cool honestly because I love baseball and that's just more games for me to go to and cheer for my state. I'm a bigger fan of one of the teams than the other BUT if my state is playing you, I'm cheering for them ESPECIALLY if your team is the NY Yankees. So this Summer, my Dad scored free club level tickets to the team that is less popular, but they were playing the Yanks so I jumped on the bandwagon and bought a shirt. We took pictures before the game and one of them was super cute so I used it on my profile. The other day I was messaging a guy who said he was a lot of fun and he like girls that were sassy. I'm pretty sassy, I know you don't know this yet, just trust me. Anyways he was only sending one word answers so I told him to get back at me when he was feeling more lively. He writes back and says something to the effect of "Oh, already getting sassy are we? Fucking *insert team name* fan." Ummm, seriously? Did he just try to insult me based on a team that he thinks I like? So I write him back of course and say something similar to that and he informs me that it's called fan bashing. I had already explained the situation, why I was wearing the shirt, where my allegiance lies for baseball etc and yet he continues with his "fan bashing". First of all, I don't love any team enough for someone to truly insult me by insulting them. Second of all, why in the world would he even think that was remotely ok to do? He also told me to take the picture down if I wasn't really a fan. Y'all, I was laughing out loud reading these messages. I told him he was and idiot, gave him enough time to see it and then unmatched his dumb ass. Dodged a bullet, or a foul ball, there! See ya soon!