Dang, this is a site I found just yesterday while on my porno travels, and fuck does it kick ass! The premise: Randy Soccer moms and the like take a shine to their son’s girlfriends. Once they get to know them and the girlfriend’s feel comfortable in mom’s presence, mom sends the son off on a long errand, or just invites the girlfriend over for a girly chat. That’s where the fun begins, because mom isn’t after a chat, she is after her son’s girlfriend’s pussy! Quite a mouthful to say, and quite a mouthful for both mom and girlfriend as it turns out 
Enjoy the above sample of a real MILF lesbian fucking her son’s girlfriend, (just press the ‘play’ button) and if that’s not enough for you, there’s a bunch more free movie clips at Mommy Loves Pussy