Hi forum peoples, I've never been here before but I figured this was as good a place as any to look for advice. This is hardly the most severe problem in the world, but it was bugging me so I thought it'd be nice to have some people to bounce questions off.
I'm a guy, 20 years old, but this seemed like more of a teenagery kind of problem. I've noticed recently that my (female) best friend's younger brother seems to have a crush on me. He's about 14, I think; I've known him for 7 or 8 years. Whenever I've been around her family recently, I've noticed this. At first I thought it was just your typical "younger kid thinks older guy is really cool" sort of scenario, since he's always seemed to enjoy talking to me when I'm around anyway. But lately it's been different. He stands/sits quite close to me when he talks to me, he seems extra interested in my opinions, and when I was with their family at a vacationy thing, he seemed a bit put out when he learned he wouldn't be sleeping next to me. None of this really bothered me, it's kind of endearing really, and it seems pretty harmless.
But the other day I was hanging out with them and he was acting in a way that switched me from thinking "huh, he seems to be acting a little different around me" to "wow, this is getting really obvious". My friend and her family were joking around and putting their heads on my shoulders (don't remember why, honestly) and her brother did too. And then stayed resting against me after everyone stopped until I had to subtly shake him off. And when I left he wanted to hug me, which was a bit odd, as we had never done that before. But I figured why not?, so I did. And then as I was actually walking out, he ran back up to me and hugged me again. He tried to play it off as a joke but not very convincingly (I should note that both times I had to end the hug because he certainly didn't seem like he was planning on letting go anytime soon).
So basically I'm starting to think I might have to actually confront this issue if he's going to keep doing stuff like that (and maybe trying more than that). I do over-analyze things, so I wanted to ask if it seems to you internet people that I'm correctly interpreting his behavior. And then more broadly, I wanted to ask, how might I go about explaining that what he seems to want isn't going to happen? I like the kid a lot and I don't want to be too harsh. Nor do I want to make him feel like his feelings are unimportant since he's young, as I know from my 14-year-old experience that that'll only make him cling harder to his feelings. The reason I'm talking to you folks, by the way, and not his sister (my friend) is because if I'm reading this situation right, he's gay, and I don't think that's open knowledge. I'm trying to tread carefully around privacy here.
Also, I'm aware that this several-paragraph detailed analysis of a small issue makes me seem paranoid and obsessed. But this is just how I solve problems, don't worry.
Short version: What's the best way to nicely reject a 14-year-old boy? I've never done it before.