If it actually can be a bet...the story went something like this...
Before the gang was killed, when Lucas was around 16, he, his two brothers, and one other member were getting quite inebriated at said member's house. The decided to leave thier little cove after all of them were well past the point of correct choices, and payed a visit to the local pub (almost right next door to the hang-out) to exercise fake IDs. Kyle (the oldest) decided to make a move on a rare sight...a female Yamataian. What the hell she was doing there none of them knew, or ever found out. The bet went something like this:
Member 1: "I bet Kyle won't even get her name."
Lucas: "Of course he will. He's the smoothest talker out of all of us. I'd bet my own head that he's gonna get her number."
(drunken logic says betting one's own skull is bad-ass, and must properly be wagered at the most inopportune moment.)
Member 1: "Alright."
*They shake and look back to Kyle getting his arm broken, and himself being subdued on the floor.*
Lucas: "........
...aw fuck."
Member 1: "So, what's your favorite color?"