It's only "out of line" if your ex is under the impression that you're over him and perfectly ok with being friends.


If he knows you're not over the relationship and he's still behaving insensitively, then no, you're not out of line. Not at all


If you two were really just friends, you wouldn't care who he dates, like he said, you'd even be happy for him, because it wouldn't even feel disrespectful at all.


I think the real issue here is that while he has moved on, you profess to have done the same, but have not reached that point fully yet.


IMO your friendship is either a farce or not fully formed yet, so better you give him an "eviction notice" instead of watching him torture you day in and day out.