User blog comment:Kaido King of the Beasts/Chapter 770: All The Fights You Never Wanted to See/@comment-99.243.126.199-20141211211825/@comment-21119641-20141211215016

At this point Luffy doesn't want to hit Bellamy as he sees the latter as a friend, and for the honor he has left for Bellamy who admires Doffy, Luffy did let Bella hit him. Thats what I think