Voyeur ideas?

So my girl has been talking to a black guy and they're meeting tonight. She says that this is just to see if she's comfortable with him, that there won't be sex. So my real question is, if he's not comfortable with me watching them fuck, how can I do it without getting caught? She would know, but we don't want him to. The only thing I can think of is the fucking in a park while I'm hiding in the woods. She lives with roommates, so I can't really hide in a closet or anything like that. Anyone else have any ideas?

It seems to me that she just says to him that you get to watch or he gets no pussy from her. Or maybe she can videotape with a tripod it so you can watch it later.