Machine Gun Kelly is Joined by Girlfriend Megan Fox at Launch Party for His UN/DN LAQR Nail Polish Line

Machine Gun Kelly has the support of his girlfriend on his big night!

The 31-year-old musician and Megan Fox coordinated in black outfits for the launch party for his genderless nail polish line UN/DN LAQR on Saturday night (December 4) in West Hollywood, Calif.

PHOTOS: Check out the latest pics of Megan Fox

Other stars at the party included Avril Lavigne, Charli D’Amelio and her sister Dixie, Chase Hudson, and Jessie Jo Stark. Guests at the event sipped on Casamigos cocktails.

A few days before, MGK was joined by his 13-year-old daughter Casie at the premiere of his new movie, The Last Son, in New York City. See the photos here!

You can shop MGK‘s new nail polish at UNDNLAQR.com.

Click through the gallery for 15+ photos of Machine Gun Kelly, Megan Fox, and the other stars at the party…