I went out to dinner with a Marine. He looked across the table and he goes, "I could kill you in seven seconds." I go, "I'll just have toast then."

The joke hinges on an abrupt shift from a macho, threatening boast (“I could kill you in seven seconds”) to a mundane dining decision (“I’ll just have toast then”). By treating the threat as if it were a comment about the meal, the speaker deflates the Marine’s intimidation and reclaims control through wit. The line also plays on the social awkwardness of a dinner date where one person performs toughness; the punchline suggests that, in the face of performative aggression, the safest or simplest response is to disengage—choosing something plain and non-confrontational. Overall, it’s a compact example of humor as self-protection and as a critique of needless bravado.