Maybe. I would talk to the girlfriend's parents. If she is not out of the closet to them, absolutely not. But if they have an open relationship with their daughter and are comfortable with it, and they understand what the two spending the night together could mean (and my daughter and I were comfortable enough to discuss these sorts of things as well, and she knows how to be cautious and safe in her decisions), then as long as it's a supervised environment with parents in the house... I might say yes.That being said, I feel similarly with straight / same-sex teenage couples. Well, older teenagers, in both cases. Like....16+. If both sets of parents are comfortable, on the same page, and have an open relationship with their children.... I would rather have a relationship with my child where I can feel comfortable that they are being safe and cautious than running around making bad decisions on their own because they don't want to tell me.