Snapping off a TV show we were both watching midway through it without a word to me first.

Was watching a show together, he got an IM. Didn't want to IM back, so had me call the person to talk with them about the IM. Show was on Tivo so it was paused for a few minutes while I talked on the phone. By the time I was about to hang up he snaps off the show without a word to me, and picks up his guitar and starts playing it. I say it was rude and inconsiderate, he thinks it is perfectly acceptable.