I'm not a parent but my partner is.

I remember being amazed when his then 17 yr. old son shared his bedroom with his girlfriend (same age) several times.

The discussion on birth control needs to come up sooner, not later, no matter what is decided by parent on sleepovers.

Though hormones are raging then, at the same time, some of these kids hang out in big crowds (at least his 2 kids each did) and have many friends that do lots of (harmless) stuff together. The advantage of 2 near adult teens at home with parents around...is that you know they aren't getting drunk (which can lead to weird/terrible stuff when no parents are around).

I'm sorry to bring in alcohol into this but there have been some highly publicized just awful stuff in the cities where I've lived involving teens.