[joeysteele]

Actually he came out later and sat with Liz.
Then although he clearly hates the song, when they were playing 'I'm in the mood for dancing',(for the life of me I saw no reason to butter up Linda and play that anyway), Jim couldn't help himself also nodding his head a bit and singing along for a line or 2 while sitting with Liz at the table.

I know a lot of people like Jim who clear off when the party starts and dancing takes place then they come back later when things have quietened down a bit.

Jim doesn't, clearly, like most of the music that gets played in the house so if he genuinely doesn't like the music why on earth should he stay there.
He went off into the bedroom and didn't spoil anyone elses enjoyment.