Atta boy! My kind of friend! Boot the leechers! I was doing a nightfall with a guy and he sat around, and did nothing the whole way through. After the boss was 80% dead his friend joined him and the boss was dead by the time he finally landed. I booted both after the boss was dead, but rewards weren't given yet, and oh man the fish in the ocean started to die, because they took all the salt. TLDR: don't leech and you won't have a problem.