Did I do something wrong?

My baby daddy and his new gf came over yesterday to pick up our 2 kids, and I’ve only met her a few times during the cold weather season. It’s hot out now, so I had on shorts and a sleeveless top.

She goes: oh, I didn’t know you and Steven have the same tattoo.

Me: yea. We both have these 3 the same but the one of the kids is my favorite by far!

Her: mhmm cute.

My ex texts me later saying “thanks a lot for opening that can of worms blah blah. Jess is pissed about the matching tattoos.” I go “I’m sorry. I didn’t mean anything by it. Am I supposed to cover my arms whenever she’s around?”

He goes “wtf you knew that would piss her off.”

Which I didn’t. I don’t know the woman. We don’t communicate. I’ve never tried to piss her off in the past. He continues “she’s even asked me if I’d get them removed” so I said “ok get them removed? Who’s stopping you?” And he flips out and goes “I’M NOT WASTING TONS OF MONEY TO REMOVE TATTOOS THAT I LIKE”. And so on and so on he went. Going off on me.

I think this anger is misdirected, but did I do something wrong here? Am I the asshole for her noticing my tattoos? Or not covering myself?