Oooh, great question! I love Lover's Spit by Broken Social Scene, the song that plays at the end of 308 when Brian and Justin get back together. Most of the interpretations of the lyrics that I've found seem to be saying it's all about casual sex; to me, it's not. I think it's about being sick of casual sex and being ready for something real, which is exactly how I feel about Brian and Justin's relationship at this point. Justin isn't expecting, nor does he want, romantic picnics on the floor and making love under the stars; he wants something real, he wants Brian. Brian doesn't want to psuh Justin away and pretend he doesn't care for him; he now knows how much he misses Justin when he's away and is just one step closer to admitting his feelings for Justin.
You know it's time That we grow old and do some shit I like it all that way