Sissy coming into town!

My little sister is coming in town on the 18th of feb and I texted me boyfriend tht she was coming that weekend and he told me “omg yay idc 😂” & I thought it was so rude of him he could of said like oh that’s cool that she’s coming. Or something else.

I know why he said it because my boyfriend and her boyfriend almost go into a fight and my sister told my boyfriend that he wasn’t shit in our family. We do have a daughter together so he is in our family. Anyways since then they haven’t talked (my sister & my bf) but my boyfriend told me a while back that he’s not even mad at her. But I felt like what he told me was messed up I never tell him stuff like that when it comes to his family.