It's her roommate.

"Thank goodness it's only you Amy" Ellen says with a sigh of relief.

"Wow, you two didn't waste any time" Amy says.

You and Ellen both blush.

"So that's what you mean by just a friend then?" Amy says teasingly to Ellen.

"Ellen and I are very friendly too" Amy says as she winks at you.

You look at Amy and then at Ellen and all sorts of naughty images flash through your mind.

Amy sits down on the bed next to you and interrupts your daydream, "So are we planning to do anything tonight or should we just stay here for a while?"