How would you feel about your man making up names with a female friend for their “fake child”

My boyfriend suggested I make this poll to show me that I’m overreacting about a ‘what-if’

We were in bed and he asked if Bailey was a real name. I said “yeah why?” And he didn’t answer and went back to his phone. I asked why again and he said “I can’t really remember why I asked that” anyways after pushing some more he said he was making up names with a friend. I read the convo and it’s his female friend and they were putting there names together to first name her new dog and it eventually turned into them naming a kid if they ever had one together. I’m just a little ehhh about it.

We’ve been together for a little over 3 years and this female friend has been in his life since middle school.