<human>: I have a friend in my hometown who is in a LTR with a guy who lives across country for work. 

Recently the girl and I have been seeing each other a lot more than usual, because we've both been lonely a lot lately. 

Last weekend we were hanging out casually, and I suggested that next weekend we go out to a bar with a group of other people for drinks. A few days later, she said she'd be more interested in something more quiet, maybe we could meet at my place for drinks, call in a pizza and watch a movie.

Not going to lie, I like where this is going.

Now, I should say I'm not comfortable with being someone she cheats with. 
But I do know that open relationships are a thing that couple's do, and her boyfriend may have given her his blessing to go after other guys.

The thing is, I don't know if this is the case. She could just want to hang, and see me in a platonic enough light that she can do that one on one (and I have no problem with us being friends).

So, how do I tell that she's open to, and interested in, sleeping with me? I can't just ask her 'hey, are you and your boyfriend exclusive?", and similarly, she probably can't just drop "oh hey, my boyfriend said I can sleep with you". 

This is some prisoner's dilemma shit right here.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Girl with boyfriend out of town, want's to hang out under some intimate circumstances, how do I find out she's in an open relationship without offending and risking a perfectly good friendship?