If you've only been together for 3 months then I'm sorry if she asks him out to dinner then they still have feelings for each other. Also if you "took" her from him then clearly there will be some hard feelings between you and her ex so he will most likely still try to flirt and win her back. Bad idea, tell her you dont like the idea and if she doesn't care then leave her.

Don't be mates with her ex trust me. It'd just be another way for him to worm his way back in.

Whether friends, family or exs' they always interfere with relationships.

I bet you don't want to sound too over protective though do you? Just tell her straight how it would make her feel if it was the other way round.

logan111logan wrote ####UPDATE###!!!!!!!
So she went to dinner with him even though I didn't want her too
She felt like that's what she need to do

BTW she didn't dress up cute she just more jeans and a t shirt

But from what she says he is more jealous of us and he wants to become friends with me

Everything is going great we are closer than ever
Basically just have to trust her
And if she cheats or whatever it's not meant to be
Thanks for everyone's help

I bet he wants one more piece of your girlfriends cheeks



*Edit*
I have never seen a community come together and bond with this mans problems better than you guys.