Based on what you're telling us now, then I'm coming around to the proposition that you should leave (to make a point) and then have a firm talk with him in the coming days.
If I was your bf in that situation, then I would feel immense guilt at having, essentially, abandoned you in my parents house, just to shoot the shit with some friends that I can see some other time. I know that a DJ sounds fun, but it's deeply unsettling to me that he showed disregard for your feelings.
Like you said, although you didn't spell it out, it looks like you had a date night planned for him, and he walked away from it. I don't know. It's not something I would had done lightly. I, at least, would've twisted your arm into coming with me, so I'd be able to enjoy myself at the party, knowing that I didn't leave you alone, and still indulged myself on going to the party. Basically, he chose the most callous option, which was just leaving you.
The fact that he also didn't thank you for dog sitting leads me to believe that he really is just a jerk. And if you can see already that he'll come back tomorrow, and just apologize about the whole affair, then that's almost equally as troublesome as him having precipitated the whole fight to begin with. It's like he knows what he did was wrong, but he still expects for you to suck it up and just accept an apology. You have to wonder... will he do this all the time in your relationship?
If I were you, I'd reconsider this relationship. You need to have a talk with him, about his priorities, and whether or not you are among them in his life. You need to press him on whether he really thinks that flaking out on you is acceptable behavior. And don't just accept a sheepish response.
It's important to be compassionate and have a heart, but it's equally important to have a spine. Don't let your boyfriend treat you like a doormat. You deserve to be a top priority in his life, and if he won't give you that, then look for someone else.