Tess: He was taken off the Dutch ship in Martinique......and died a week later of consumption. Gemma: Oh... He drank too much? Nigel: No. Um... Consumption, darling. As in tuberculosis. Not to be confused with consuming, as in guzzling. Gemma: Oh, man. I'm so dumb. Huh. Finn: You wanna hear dumb? I used to think that it meant he died having sex, as in consummating.
Tess explains that Sebastian died of consumption which Gemma thought meant of overdrinking. Nigel clears that up but Finn explains that he thought that meant he died while having sex.