Marshall, a sweet but bullied teenager, turns to Trevor to fix up his left-wing mom, Hallie, with his boxing instructor, Clint, the sperm donor who made Marshall's birth possible. They are compatible in every way until Hallie discovers that Clint is a Republican and she breaks off their promising romance. Meanwhile, Claire's free-spirited mother, Liv, a woman with a lust for love like Trevor's, moves in with Claire after yet another breakup with her latest boyfriend.