but hey, it was on the band bus

Phrase stating that you should void what happened and it should not mean much. The band bus is merely a reference back to a bus driving home on a dark night. So making out with that girl next to you was not a big deal.

Guy: i cant believe Sarah lol
Girl: whattt?
Guy: makin out with robbie
Guy: and me
Guy: a week after me
Guy: in time
Guy: but hey
Girl: told you!!
Guy: but hey, it was on the band bus
Girl: yeah the band bus of crazy horny maniacs lol