I don't even know how to say this, nor how to feel about it. 

My friend celebrated his birthday a couple months ago, so he invited me, his girlfriend, and a couple other fellas for a celebration. Turns out, he wanted to do some stuff with his SO because the girl is pissed on him for not sleeping over. He pleaded me to guard the door so his parents won't walk in on them.

The thing is, there are other people in the room just then. One of my pals was playing, another is talking to her girl via phone, and me? I was using fucking reddit. And for some reason he thought I should be the one protecting their asses from getting roasted to oblivion because what I was doing "is the least important". So while they were out there laughing their asses off from what the fuck they're doing, I'm supposed to be outside, guarding them from getting walked in on.

It's been bothering me for quite some time now. Aita for feeling pissed about this situation? 