Gemini guy friend; How to stay on the good side

Anyway, fast forward to now and a Gemini friend and I are chatting/hanging out again after a month long hiatus. A bit of back story. We used to hang out EVERY DAY for like two weeks. I'd spend the night at his house, we worked together so we'd just chill all day, and then leave and go drinking etc afterward. We'd drive around until 1-2 in the morning on the back streets talking about everything and smoking out.

I told him I was starting to "like" him in that way, but I wasn't surprised in the least when he invited me to a party he was attending with a girl he was actually trying to date. Yeah, I was a bit taken aback, but I still showed up, albeit a few hours late (I had stopped at a pub before hand and got caught up with this gorgeous Greek guy...okay I digress), a little tipsy, carrying two 24 packs, a big smile, and my "party look", ready to go.

Can we say ice cold? He spent the whole night being aloof, stand offish, and a bit dickish, even though I was laughing it up and chatty with his date, and just mingled with his friends instead of hanging all over him or some such nonsense. I really didn't know what he expected me to do, as it seemed like he just got madder with me as the night went on. I was trying to be respectful of him being on his date and give him space to get to know his lady. He even later confessed that his friends "loved" me, so I didn't think I embarrassed him or anything.

After that night he didn't talk to me for a month, and I never texted him, as I assumed he was busy and would get back into contact if he wanted to.

Now out of the blue it's texting, calling, wanting to hang out, all over again and I'm like "awesome!" We were supposed to chill today but I'm cramped up and feel terrible. He was almost on the verge of begging me to just let him come over and I said we could catch up later in the week. We chatted for a good hour and a half on the phone, before we hung up, but I felt terrible for canceling on him again (we were supposed to hang out yesterday too...) Really, he's so much fun to be around and, as a Virgo, whenever I make a true friendship, I'd hate to lose it.

So for Gemini's how do I stay on his "good side"? Did I just shoot our friendship in the foot again?