At the risk of stating the obvious, can I encourage you to assume that your 14yo has clocked you as sexually attracted and is at least considering the possibility of doing something about it. If so, you need to be very cautious about how you interact with him when there aren't others around; current 'child protection' policy at some churches says that you should never be alone with a child, and there is some wisdom in that. And if you are only in contact with him in church buildings, you are going to lose very little in return for being kept safe from total disaster.

Another issue is the stance of your church towards gay relationships. Perversely, the more rejecting your church is, the safer you are from public comment, because

a) it means that his actions are less likely to be interpreted as sexual
b) he is more free to be appropriately affectionate and you can accept his behaviour as such (e.g holding hands)

A wider issue is the sex education that your church offers in its youth program: has he heard a message that he can cope with, or is your church so rejecting of gay people that he's feeling inherently condemned? If it's the latter, then he's got a serious problem: sadly such churches do still exist, and if yours is one, he needs to hear an alternative Christian perspective (and you almost certainly need to change churches, though his presence means that you shouldn't do that too soon!).

And to continue to state what I hope is blindingly obvious: your primary concern is what is best for him. Hopefully that won't conflict with what's best for you, but if there is such a conflict, us adults need to be willing to choose what's in the boy's best interests. Easy? Of course not - but we serve a Master who told us to take up our cross.

I've probably said far too much and stated the obvious. Please don't hear me as suggesting your relationship with him is necessarily a bad thing; as someone whose teenage years were massively eased by a non-sexual friendship win adult who I now know was a BL, I have no qualms with arguing that we can be a great blessing to boys. But in choosing to work with boys we are taking a risk; we need to be aware of the risk and look at it rationally, and from GOD's perspective. May you continue to be a God's gift to him and others.