What would you think if your SO was offering to hang out with another girl to get their kids together?

Sorry if the question is somewhat hard to follow.. today my sister sent me a screen shot of a post in a local group where a lady was complaining about people being mean to her daughter at the park. So my SO commented “let me know next time you go and I’ll meet you there with my daughter”…

Is that weird? I did ask why he wouldn’t have offered for ME to hang out with them instead but he just kind of guilt tripped me..

side note*we’ve been together 10 yrs, 3 kids together, live together, so it is a serious relationship. But I think I can also be an over thinker which I’m trying to fix.