Update: So the whole "going to the movies with him and his group of friends" wasn't as awkward as I thought it would be. In fact, it wasn't awkward at all!
His friends were nice, friendly, and talked to me the whole time. They definitely didn't make me feel like an outsider or anything, so it was nice.
As far as progress between the INFJ and I goes, nothing monumental happened.
He sat between me and one of his friends (a girl) but throughout the movie and after each commercial he would whisper and talk to me, not her. But I do that with friends as well, so no big deal.
I wasn't "touchy" at all with him since I'm not a touchy person in general and all his friends were around. But I did see his legs shaking nervously before the movie started (probably because he was nervous about the scary movie) and I put my hand on his leg and jokingly asked if he was going to be okay.
He looked surprised at first, then he started apologizing for shaking. And I just tried to assure him that I was only joking and that it didn't actually bother me.
At the end of the night, driving in his car, it was just me, the INFJ, and his best friend (male). Same as before, he parked and walked me to my door while his friend waited in the back seat. Then we talked for a bit, hugged, and then he said that he was sorry that he wouldn't be seeing me again this weekend. I asked him "what do you mean you won't see me? I'll be at that one party on Saturday night and you're stopping by, right?". He said that he'll definitely try to stop by, asked me to text him the address again, and said that he meant that he won't be seeing me the whole weekend or something like that. 
The pre-hug walking to the door conversation atmosphere felt a little awkward to me. Although, I'm not sure why he would be feeling awkward/nervous.
Unless maybe he sensed that I liked him, but he didn't like me, so he was nervous that I would try to...do something?
I don't know
I think I had a bad combination of being dense when someone showed interest, and overly subtle in expressing interest.
When older, I just took greater risks, and lucked out somehow.
I'm the same way.

Hopefully, I'll luck out somehow too though
Wow. You know, every single girl I've dated (I say it like it's a lot... only 2 actually) has never been transparent with me. It's always been this, "Oh God... what's going on in that head of hers...", and I've always had to drag it out through a long process, it's like chewing thumbtacks.
I think it's awesome that you like the infj so much. I think he's a pretty lucky guy. At least you've got your confidence to keep you strong when you ask him! I'd probably chicken out at some point and pretend everything was fine (or that there was nothing to pretend about) like a good infj.
Thanks!

This will be the first time that I've actually told someone that I like them (usually they just tell me that they like me or I don't think they reciprocate my feelings so I decide not to tell them about mine)...so I'm definitely still nervous in that sense.
I've been trying to decide on how I can say it, while accomplishing these things:
1) Getting the point across clearly, obviously
2) (If he responds by saying that he doesn't like me) Reassuring him that we can still hang out, and he doesn't have to feel awkward around me or avoid me in the future
So far I've come up with the following statements:
1) "So...you know I like you, right?" - said half-jokingly, half-seriously with a smile (to make the mood more light-hearted)
2) "So...I just wanted to let you know that I like you" - pause for a minute to gauge his reaction then move on (follow it up with something like "so do you want another drink"?

or with a lighthearted or self-aware jokingly self-deprecating comment)
I don't know, how do either of these sound? I plan on asking him if he wants to go see this play (+dinner) with me next Saturday, so that's when I would tell him. Hopefully he's not busy next weekend and can go with me. I'll probably ask him about it on Wed!

I plan on telling him that the whole night will be "on me", paying-wise, since I owe him so much already (meaning: he's paid for me the last 4 times we've "hung out" both one-on-one and with other people around) and I feel bad.