Would you tell his girlfriend??

So I met this guy while I was in college and we would text back-and-forth a little bit flirty until I found out that he had a girlfriend the whole time and we stopped, I ended up getting with my boyfriend and fast forward to now, my bf and I are expecting a second baby girl 🙏. Anyway, he would pop back up every now and then and send me messages or whatever and even tried to flirt with me when I told him the first time I was pregnant with my daughter, which seemed really weird so I stopped even messaging him and blocked him on Snapchat. However, he has me blocked on Instagram, and every now and then he unblocked me and will like my pictures or DM me heart faces and then will block me so I can’t see the message anymore and it doesn’t show in my dms. He has done this a few times now and it’s only a matter of time before he does it again I’m sure.. Him and his girlfriend have been together for probably 6+ years and I’m wondering if next time he does it I should tell her? I’m perfectly happy with my boyfriend and there’s no way for me to block him when he keeps blocking me, so I have no control over this happening really.  So I was thinking the next time he does this, I will just screenshot the notification and send it to her and tell her what has been going on because at this point I really don’t appreciate him doing that because it can also cause issues in my relationship. If, for whatever reason my boyfriend were to get the wrong Idea if he saw him message me.