So, there's this... elephant. No just kidding, it's a guy. Now that's I've hijacked your attention, I can get down to business. I've been out on a casual date with said elephant (no really, it's a guy) three times now. The problem is, I don't really like him in "that" way. When he first asked me out, I wasn't sure, so I agreed. And then I kept doing it cause I thought maybe some feelings for him would come a little later if I got to know him better. They haven't. He's cute, but instead of my brain going "OHHH I LIKE YOU THEREFORE I MUST KISS YOUR FACE NOW!" I think "You are nice, like my brother. I wanna be your friend." I have no idea how to communicate this to him, and I don't want to crush his feelings. It took him weeks to get the courage to ask me out and he seems very sensitive. I even pretended to have to go somewhere when he asked me out a fourth time because I'm a coward. He also texts me constantly, and I don't know how to end our conversations. I don't want to hurt him, but I feel like a jerk for leading him on. If I have to tell him, how in the heck do I do that? It will be especially bad because I see him every day in class, a class that's very small where we work as partners all the time... so awkwardness between us would escalate pretty quickly, I think. So Jono, is there any way I can fix this mess?
You can do this as bluntly or as gently as you want, Sparkler; it's just like ripping off a Band-Aid. Well, except for the fact that you're actually ripping it off someone else. And the guy has no idea you're going to do it. And also he is probably sitting there thinking about how you two will get married. But still, the same principle applies; you can be blunt and get it out of the way, or you can be indirect, to try to preserve his feelings.
For the record, I respect that you gave this guy a shot; sometimes you're not into a person at first, and then you hang out a few times, and your brain is like, "Oh! Ohhh. Here, have some brain hormones," and then you look and him and immediately want to do makeouts. Anyway, you're not a jerk for how this turned out—you had good intentions and you gave him a chance when you weren't obligated to, and he'll respect that. Well, first he will lie down in the dark and groan for a while, but eventually he will respect that.
Here are the two general ways to go about doing this. I've included a third method for cowards because I am a coward.
Ripping off the Band-Aid
If you were to pose this question to a regular advice person, or indeed almost any responsible human adult, this is the method she'd probably recommend. If you're direct, and you say exactly what you mean, it leaves no room for misunderstandings. Of course, I never actually use this method, because I dislike conflict so much that if I order a club sandwich, and the waiter brings me a single shoe on a plate, I will just sit there and eat my shoe in silence. But if you want to know the "right" answer here, it would be to tell the guy something like this:
The last example is somewhat more blunt than I would recommend, but you get the idea. The point here is to make it explicitly clear that you don't want to pursue anything romantic, without leaving any room for doubt on his part, while also saying something vaguely positive.
Removing the Band-Aid gently
If you want to spare the guy's feelings as much as possible, you're going to have to lie a bit. There's ultimately no way to say "I do not like you" that leaves him feeling particularly great about himself, even when you follow it up with "...in that way." I'm not saying I recommend lying; I'm just saying it would let him down easier if you told him something like:
The argument against this method is pretty obvious: you may become entangled in your own web of lies. Also, lying is immoral or whatever. Ideally, a small lie ("I'm not ready for a relationship.") will at least be enough to make him understand that you're not attracted to him, and he won't press the issue if you do date someone else later.
Ignoring the Band-Aid until eventually it is gone somehow
This is not a great plan, but it is a plan: You could always just keep turning him down and never being remotely flirty until he understands that you aren't interested. After all, it's been three casual dates; it's not like you owe him an explanation for not liking him. I hesitate to suggest this, but if I were constantly texting some girl, "heyyy!! hey what's up!! hey!! helloooo!" and then once a week she responded with, "what," it would be pretty clear to me that she wasn't interested. If she kept saying she couldn't go on dates because her pet owl was stuck in a cereal box, I would understand that I should stop asking for dates. Of course, this guy is a high school guy, so if you tried all of that, he might just assume that you have a broken phone and a clumsy cat and are still totes in love with him. Use this method at your own risk.
You asked me how to avoid any potential awkwardness here, and I'm afraid that at least a little awkwardness is unavoidable. But as long as you're nice about it, and you reiterate that there's a lot of likable stuff about him, I think you can let this guy down pretty directly without breaking his heart into a million pieces.
Which option would you choose?