The other members of the group — Ethan, Sam, Nick, and Marianne — have done questionable things to each other, but what sets them apart is their intentions, and taking accountability despite their incredible immaturity. Ethan and Sam are genuinely in love with one another. Their actions were selfish and caused a lot of pain, but nothing they did was done out of malice. Also, they finally do the right thing, by being honest about their feelings for each other and desire to be together. Nick has deep-seated commitment issues, but every time Lisa needed him, he dropped everything to be there for her (he went to the Caymans so she wouldn't be alone; he blew up his relationship with Merrill Morgan for her; he let her crash at his place; he offered to raise Ethan's baby with her).