Honestly, if that was my neighborhood, I would seriously try to move if at all possible. Kids in our neighborhood just don't act like that at all. I can really understand why you are so anxious. It is not normal for 7 year-olds to be trying to have sex. That means they have seen it somewhere, either in person or on TV, etc. They will be curious about bodies, but they don't know about sex unless they are taught. If moving is not possible, my personal actions would be to not allow my child to play unsupervised with them. If you can make your house a fun place to be and the kids want to play there, where you can watch their behavior, that's one thing. I wouldn't allow my child to go to their homes without me, even at 7, due to the behavior you are seeing. I wouldn't let them go anywhere without me unless I really knew the family and trust that their kids are well-behaved and well-supervised. Just my opinion. Hang in there!