Keeping Up With The Kardashians star Brody and blogger Kaitlynn were among the stars at the VH1's Barely Famous series two premiere on Tuesday, 14 June.
Brody was supporting his stepsisters Erin and Sara Foster, who created the parody show, poking fun at the reality TV culture.
His mum, Linda Thompson, was married to Erin and Sara's father David Foster until 2005.
There as plenty of celebration in the family last month when reality star Brody revealed he'd proposed to Kaitlynn, following a two-year relationship.
Brody announced the engagement via Instagram, saying: "On May 4th 2016 I got engaged to my lover and my best friend Kaitlynn Carter. I couldn't be more in love with this woman and I can't wait to spend the rest of my life with her."