Bob owes Joe $5,000. one day they're walking down the street, and both have lots of cash on them. they get mugged. before the robbers take their money, Bob asks "can you at least let me pay joe here back the 5 grand i owe him first, before you rob us?"
That would be like saying "take all of Joe's money instead of mine". Bob is taking an action designed to make Joe take the strain instead of himself.
Would that be moral with strangers, even? Friends seems pretty straightforwardly douchy thing to do. Generally you'd want to cooperate and split the burden, even with strangers, right? (If not why not?)