User blog comment:Kaido King of the Beasts/Chapter 769: The Good, the Bad, and the Bellamy/@comment-1876594-20141128003449

Maybe Bellamy wants to attack Doflamingo but he's pretending to attack Luffy. Just like Luffy did with Law, attacking Doflamingo with Red Hawk.

Otherwise: Bellamy know that he will die against Luffy, but he still fights. In Jaya he said "losers do prefer to shut up and be mocked, rather then be defeated". He knows he's a loser, but he prefers to fight and die than stay quiet. It's just like "weak people don't choose how to die", as Law said to Tashigi in Punk Hazard. Choosing how and when to die is the maximum he can obtain.

PS Of course he will survive, maybe joining Bartolomeo's crew.