Star Trek Torchwood crossover.
"Your pick up lines are illogical," Spock said.
"I'm straight," Kirk insisted. He wondered how Captain Jack Harkness had even gotten onto the Enterprise.
"By the way I'm looking for a friend of mine," Jack said, "have either of you seen-"
Ianto walks in wearing a red shirt which Jack wrestles off of him.
Ianto blushed deeply. "Jack what have I told you about undressing me in public?" he demanded.
"You were wearing a red shirt!" Jack exclaimed. "Everyone on this ship wearing a red shirt dies!"
"Really?" Kirk asked. "I never noticed that."
"Still you could have told me," Ianto said.
"By the time I told you you could have been dead!" Jack replied. "Why were you wearing that red shirt anyway?"
"I was trying to blend in nearly everyone on the ship is wearing a red shirt," Ianto answered.
"That can't be a good sign," Jack said.