AITAH for calling my gf an idiot

my girlfriend and i recently went through a rough patch and she broke up with me so we took space apart. last night we had a long conversation about our wrongs and what was bothering her. we both took accountability and were having a good time. she told me she had told her friend we broke up and the circumstances of the break up. i said “you’re an idiot why would you tell people that if we were just taking space apart” she doesn’t like name calling (she has bpd and is mean in other ways) she got upset and told me she didn’t like that. name calling is a big thing in my household and the habits hard to break. i talk to my friends and family like that but my gf is very sensitive and doesn’t even joke like that. i apologized but AITAH for feeling like that was an idiotic thing to do