With my former band Filthy Cowboy Sunset we once opened for DM Bob and Jem Finer (of Pogues fame - a band that meant pretty much to me back then) with Bob's girlfriend Silke from the Watzloves, and hanging out with them was one of the least rock'n'roll things ever - but pretty great! We played on a weekday, and my band was tired from work, and they were tired from travelling, so we hung out in the backstage room and must have been a sight to see: Bob and Jem were playing chess, Silke was reading copied texts about Dadaism, our violinist was reading something else, our pianist and our drummer were sleeping, and me and our singer were just sitting there eating, amused about the scenery.
The three of them were really nice people, polite, cool, nice, funny and modest - and so much fun on stage (which you wouldn't have thought seeing them playing chess like some elderly gentlemen on the porch)!
So - hanging out with fave musicians for me was like watching TV with friends: a relaxing, funny thing, somehow without much rock'n'roll, but still a fine experience.