There’s one aspect of the holiday season that’s got Stephen Colbert seriously bugged.

On Friday’s broadcast of the “Late Show,” the comedian poured scorn on the Christmas custom of kissing underneath the mistletoe.

“This one is a messed up tradition,” Colbert said. “If you catch somebody underneath mistletoe, tradition says you can kiss that person whether they want it or not.”

“It should be called mistle-Trump,” he added, in reference to President-elect Donald Trump’s pre-election comments about being able to grab women’s genitals. “Donald Trump said if you’re a star, you can grab them by the holly and they can’t stop you,” Colbert quipped.

The comedian later said people shouldn’t call him a party-pooper due to his disdain for the practice because “the real pooper here is mistletoe,” as the word in fact derives from “mistle” meaning “dung” and “tan” meaning “twig.”

“Oooh, kiss me! I’m standing under the shit-stick! So romantic,” Colbert joked, before explaining how the plant spreads (via birds pooping the seeds out) and asking why, given its poisonous nature, people didn’t just “hang up a bag of cyanide capsules to kiss underneath?”

Check out the full monologue above.