I hope it works out as good for both you and him.

At the risk of raining on your parade however, can I encourage you to think NOW about the rules you're going to stick by when he's around. Things do go wrong - the worst case scenario is when you YF makes an explicit pass at you, and you need to have thought out how you will react if that happens. But you would be wise to think through how much touch you will be comfortable with: does his sitting on your lap seem wise? How much play fighting is safe? Is cuddling up to him a good idea - especially if he's not wearing a top. Do you encourage him to go skinny dipping - or wander round the house naked - or do you try and make that a no-no. My rule of thumb is: act towards him as though everything he is doing is totally innocent, but assume that in fact he knows what he's doing so you are prepared for the moment when it unambiguously isn't innocent. The theory behind this is that if it is innocent, then no harm is done, and if it isn't, he's going to be discouraged from exploring further if you pretend you aren't picking up any hints; remember that once you've made it clear to him that there is a sexual attraction there, then he's potentially got the power of blackmail over you.

Although one way of identifying whether there is an issue may be to see if he's got his eye on any of the girls at school, it's important to note that this is no guarantee that he won't be interested in exploring a sexual relationship with a guy. Hormones mean that sex with anybody can be attractive...

If you can get other boys along on your trips with him, this is likely to reduce the chance of anything going wrong, as well as benefiting the other boys concerned if they are equally isolated from adults.

Overall - have a great time: it's a wonderful privilege to have a boy in your life, and you can be a great blessing to him. I hope and pray that for the next few years you will be the AF that he needs as he navigates the pleasures(!) of being a teenager...