There always are huge boobs on the chick wearing the t-shirt with a stupid slogan in the sidebar page of urbandictionary. The boobs are big enough its worth staring, but the t-shirts are never funny enough to click the link.
A public request for a private conversation or meeting usually employed when in the company of others. The announcement of "sidebar" is intended to prevent others from interrupting the conversation. Comes from the O.J. trial.
Scott pulled Julie out of the party and into a sidebar to, drunkenly, confess his undying love to her.