AIO. I broke up with my bf after he called me a terrorist

I’m (F18) Irish and my bf (M21) is English. He was over in Ireland with me and we went out last night with my boyfriend and some friends to a pub. The atmosphere was great, music was playing, and someone put on “Celtic Symphony”a song I’ve heard and sung my whole life growing up Irish. When it got to the line “Ooh ah, up the RA” everyone started chanting it.

A minute later, my boyfriend leaned in, whispered “You are and sound like a terrorist just as much as the rest of the people here ” then got up and walked out. Nothing else. I msged him as he wasn’t picking up my call and ended up breaking up with him. am I overreacting, or was that completely out of line?