Throughout What We Talk About When We Talk About Love, Mel tells his wife and his friends what he thinks about love. We first hear about his ideas about love when his wife, Terri, defends the man who she used to live with. This man was violent towards Terri, but Terri insists that this violence was a demonstration of his love for her. She insists that the man did love her despite his violent behavior. Speaking about this man, she says to her husband,
He didn't love me the way you love me. I'm not saying that. But he loved me.
Mel is incredulous and, in response, says, "If you call that love, you can have it." Mel doesn't believe that love can be violent, and from this we can infer that he believes that love should be kind.
Mel later tells his friends about an elderly couple who were hospitalized after a car crash. He says that the old couple suffered horrendous injuries but pulled through because they had "incredible reserves." The implication of the story is that the elderly people managed to survive their injuries because they could draw upon their "incredible reserves" of love for one another. Their love made them resilient.
Continuing the story of the elderly couple, Mel also recalls how the man became very depressed because he could not see his wife. Both the man and the wife were covered in bandages, with only small holes for their eyes, noses, and mouths. Mel remembers being surprised when the man told him that he was depressed not because of his injuries but because he couldn't see his wife through his eye-holes. In Mel's own words, "the man's heart was breaking because he couldn't turn his goddamn head and see his goddamn wife." From this story we can infer that love can be painful or depressing when the object of one's love is removed, even if only from one's sight.
At the end of the story, Mel expresses considerable anger towards his ex-wife. We learn that he would like her to be dead or attacked and "stung to death by a swarm of ... bees." Earlier in the story Mel says that he "hate[s] her guts," but he also acknowledges that he used to love her. The implication here is that love can be painful. Long after Mel has separated from his ex-wife, the love that he had for her, or at least the loss of that love, seems to still cause him great pain and anger now. Both Mel and the old man in the car crash experience a different type of pain as a result of the loss (temporary in one case and permanent in the other) of love.