Hi Rivergirl
I have an 18yr old daughter and can definately say that when she was 16 there is no way I would have allowed her to stay overnight with a boy 5 years older and certainly not after only knowing him a few weeks! I think that before you are going to feel comfortable with this, you need to get to know him. Does he live on his own or still with his parents? Have you ever met him - first impressions? That is a big age gap at the moment - when she is 20 you wouldn't think twice about her having a 25yr old boyfriend - she still has alot of growing up to do and 16yr olds are very impressionable.