Should I ask my boyfriend to delete his ex off of Facebook?

[material grl54321]

Would it make me look bad if I ask him to delete her? I'm not jealous of her or anything but I don't want him to have anything to do with her, esp being online "friends" who don't talk. It didn't bother me before, only recently when she got engaged and he til me he felt weird about it. He had a crappy day at work all day and I think that was the reason. I know he loves me and it's a good thing he told me how he felt and I understand since it was a six year relationship where they lived together but I want him to forget it since he's already moved on.