Whenever he becomes friends with a new female I feel a giant wave of relief when I see that their married or in a relationship. It's especially good when their partner is in their profile pic with them.
When I realize some of them are cute single twenty something year olds, well I cringe and hope they're fat in real life. I'll admit that it's become my daily evil thought. So far all of them have been mutual friends with other people that I know at work, so he's just meeting people through vendors. As long as none of them have gone to comic con, dig the muppets and lost then I see no immediately threat.
Do I of course, need to friend as many males as possible just in case he stalks my fb? Umm...yes!