Back in chapter 434, Shanks meets with Whitebeard.
When he gets on board, Marco scolds him for using his Haki to knock out so much of the crew. At this point, Shanks says “You’re First Division Commander Marco, right? Wanna join my crew?” and Marco gets furious at these words.
Now, with the latest chapter’s reveal of how Roger takes Oden from Whitebeard, things seem to make more sense.
Shanks wasn’t asking Marco to join, he was reminding both of them of the time Oden left to join Roger. That explains Marco’s reaction and the bad feelings between the two, because I’m sure he hasn’t let it go.
*by FatedTitan