Over the last six months my daughter has had her friends over more often. Especially her friends who are boys. This is not a problem as they are all perfectly nice, well-mannered kids who are even sometimes amusing to listen to and/or hassle.
Two things that took getting used to with teen boys: First, they seem to take up so much more space than girls. They are all a lot bigger than my petite sized daughter but even the ones who only as tall as me seem to take up more space. In my opinion, three boys are a crowd.