A somewhat cleaned-up term meaning to make love. Said by Eric Matthews (played by Will Friedle) during a brazen and impromptu marriage proposal to his brother Cory's fiance Topanga Lawrence (played by Danielle Fishel) in front of friends and family in the "Boy Meets World" episode "They're Killing Us".
Similar to BFF, but refers to someone who you have been best friends with since kindergarten, hence the acronym "BBSK" means "best bud since kindergarten". Coined by Ryan Laserbeam (played by Matt Shively), in reference to his best friend True Jackson (played by Keke Palmer) on "True Jackson, VP".
Hey guys, you have gotta meet my awesome bud Doug sometime. He's my BBSK.