My 20 yr old DD has been having a flirtation with a boy a few years older. She's known him quite a while. They've had a few dates and this flirtation has been going on for quite a few months. However he is really bad at letting her down and saying they will go out, and then they don't. Tonight she was in the local pub and he was there and they were together with a group of friends. He couldn't get a taxi home and as we live within walking distance, she texted me and asked if he could stay. We have her friends staying all the time - male and female, always sleeping downstairs on the sofas. But on this instance she asked if I could go upstairs tidy her bedroom and change her bed, and could he stay up there - but that nothing would happen. I said no - that couldn't happen. Am I being unreasonable? She is a month off 21, so not a child. But they're not in a proper relationship. She is mad with me because she had already told him it was ok, and then I said no. And I pointed out that I could drive him home anyway, so there was no problem in him getting home. The problem is that he's a bit older than her so I know she feels like she has to act older - and she sees that as acting older. So she's embarrassed that she had to turn around and tell him he couldn't stop, and really really angry with me. Was I wrong to say no?