Your daughter being a cheerleader in high school means nothing when it comes down to being a responsible adult. I would most definitely have the sex talk with her.. Also since shes acting like an adult... maybe you might need to force her to start paying rent (To encourage her to get a paying job if she hasn't already) to continue living at your house. I would also invite her boyfriend over to your house, and get to know him a bit more. First thing you should ask if he currently has a job? Because that's vastly important if your daughter and him are actively having sex... god forbid your daughter gets pregnant by him... whose going to take care of the baby? Is the boyfriend responsible enough to stay behind, and help care for the kid for the 18 years of the kids life... or will he go cold feet, and take off leaving your daughter behind? Either way...