<human>: Can you give me the gist of the text in a nutshell?

We have been together for two years. We do not live together. Yesterday was his birthday. I brought him over a cake and got him a present and we had amazing sex. Afterwards, his best friend John called him and asked him if we wanted to go to some house party with him and his girlfriend Sam. We agreed. I really am not a fan of parties. I'd rather casually drink and smoke in a small group than bustle around in a house party, but I decided to go with him cause it was his birthday.

A lot of people began leaving after 2am. I had to be at work by 9am to do a short project that needed to be handed in tomorrow, so I told my bf that we should head home. But he is talking to Sam and John about leaving here and going back to his place to smoke. I tell him I have to go home and asked if he wanted to come stay over at my house. But then he tells me, "Well, hey, I gotta go. Thanks for coming out here with me." And he goes and gets in John's car and they leave me. They don't even wait for me to follow them out. I had no idea where I was. 

Well, the entire drive home, I was just so *pissed* that he ditched me like that to go smoke. I called him when I got off work this morning. He didn't pick up. I decided to buy us lunch and go over to his house, but he wasn't there. So I went home. He text me an hour ago saying, "Last night was great." I said, "Which part?" And he said, "Oh well I guess you weren't there for the best part, my bad." And I text him, "Thanks for that. Bye."

I haven't talked to him since. I am so pissed. How do I handle this.
<bot>: boyfriend ditched me after a party to go continue smoking with two other friends and then rubbed how great it was in my face. I'm pissed.