Husbands old flings messaging him on facebook

He does have many friends and followers on facebook but deleted most of the girls he had a thing with back then but we didnt really care anyway I'm not a girl who says find every single one and block them all he aint got no time for that and I dont either and he mostly doesnt even remember the girls because he didnt have much to do with them besides having sex with them during school time.

I dont know if its my hormones or not but there was this girl who constantly sent him friend requests and I told him and he said just block her because thats what he does when he thinks thats a girl from high school.

But I told him I wanna know what happens when I accept the friend request and he said okay because he doesnt hide anything and that girl immadiently messaged him and she was like "Heyy I just saw you on facebook just wanted to know how you're doing and if you've got time for a little bit of fun like back in the days" and my husband and I just laughed and some friends came to surprise us that minute so I just forgot about that chick.

The other day when I was on facebook she texted him again and sent him a picture where she was like pretty much naked and pulled a sad face and was like "you're ignoring me but I'm definitly better then your fat wife" and that made me so angry.

Not because she's calling me fat I don't care I'm pregnant she's just being stupid but I can't believe people would do that and knowingly try to sabotage a marriage by inviting the guy out to have sex with him because of his recently very good going job.

I looked through his other chats and scrolled down and saw some other girls always messaging him saying stuff like that or just sending him pics, he did block them all and didnt message one of them back but I feel kinda bad now, I dont know what to do...

I know he'd never ever cheat on me but its still hurtful.