Machine Gun Kelly & Camila Cabello Perform 'Bad Things' on 'Fallon'

After turning up the heat on the infectious “Bad Things,” Machine Gun Kelly and Camila Cabello brought their collaboration to life on Wednesday’s “Tonight Show.”

The Fifth Harmony songstress started the performance on top of a piano, explaining the ins and outs of a “complicated” relationship. “Am I out of my head?” she asks. “Am I out of my mind? / If you only knew the bad things I like / Don’t think that I can explain it / What can I say? It’s complicated.”

Then, donning a dapper suit, MGK came through with some rhymes about a fiery love affair. “I got what you dream ’bout,” rhymes Kellz. “Nails scratching my back tat, eyes closed when you scream out / You keep me in with those hips / While my teeth sink in those lips.”

Backstage, Camila and Kelly had some fun with “Fallon” during a “Would You Rather?” segment, where they talked about cows, Auto-Tune, eyelashes, and flights.

Released back in October, “Bad Things” has been streamed over 20 million times. While Cabello continues her success as part of Fifth Harmony, Kellz is on a worldwide tour through Dec. 21.