depends if I liked them or not lol. No it wouldnt bother me as I trust my man 100%. there is one girl thats his ex that I wouldnt want him to be friends with as I hate her but not because of him. She tried adding him although she cheated on him, and he told me and I said 'do what you want' he then ignored her. If your partner really wants to speak to the ex they dont need to be friends they can still private message.
I'm face book friends with my ex-husband, and at least a couple of old boyfriends... However, I don't have a boyfriend at the moment to get in a pickle about it so, no drama there then...!
I'm not on it but my wife is and from what I can see of it it means nothing to be friends with people, it's basically the done thing to be friends with almost anyone you even half know.
theres nothing wrong with remaining freinds with your exes, however when they cross the line and start flirting and reminding eachother of what a good time they had together, then that becomes a problem