Geez, talk about passive-aggressive. If you want to know if the guy’s interested in hanging out on NYE, just ask him already. Most guys — especially ones who are, for all intents and purposes, in a relationship and therefore not thinking about whether they’re going to find someone to sex them up on NYE, don’t really put much thought into the occasion. It’s like Valentine’s Day that way. Women stress and freak out about it a lot more than men do. For example, I’m sure they exist, but I’ve never met a guy who starts shopping for his NYE outfit right after Halloween, or agonizes over whether he could possibly get away with going bare-legged for the night, or if his eye shadow is sparkly enough. So, it could be very possible that your dude either hasn’t gotten around to thinking about NYE yet or, if he has, he’s simply assumed the two of you are going to do something together and maybe you’ll do the organizing and let him know what’s up.
But perhaps you’re writing because you’ve had suspicions your dude is over it. Or maybe he’s the kind of guy who never plans or organizes everything and once, just once, you’d love it if he took the initiative and planned a nice night out for you two. And if you’re feeling either of these scenarios, you’re still being passive-aggressive by setting up this “trap” for him and watching and waiting for him to walk right into it.
If you really want to get to the bottom of his behavior, just communicate with him already. Tell him what you’re feeling. You’ll get your answer a lot faster that way and can plan accordingly (i.e. make sure you’ve got something else to do that night than sitting home alone stewing in your own anger if it turns out he’s made plans without you).