Miley Cyrus & Justin Gaston Sing-A-Long

Miley Cyrus and her BFF Mandy Jiroux posted another new video on their popular YouTube show. This time they featured a special guest: Miley's 20-year-old boyfriend Justin Gaston.

The underwear model sings his new tune "You Make Me Happy," while Miley dances and sings along.

Check out the vid above!