Brandon Jenner has married his pregnant girlfriend Cayley Stoker.

"Happy Birthday to my beautiful wife, Cayley. I have discovered a whole new level of happiness because of you," the reality TV star and musician captioned an Instagram post featuring a gallery of photos led by one of the couple hugging and dressed in what appears to be wedding attire.

"You are smart, kind, funny, driven, caring and super pregnant at the moment with our twin babies!! I will forever cherish what we have together and am so looking forward to celebrating every one of your birthdays with you from here on out."

"Eva, Onyx and I are so unbelievably lucky to have you in our lives. Thank you a trillion times over for loving me the way you do."

A day earlier, Jenner shared a sweet video of him dancing with Stoker, alongside the message, "It's official," with heart and diamond ring emojis.

"We wed at the Santa Barbara Courthouse on Jan. 21 with my daughter Eva and Cayley's grandmother, Joan, as our witness," Jenner told on Sunday.

Jenner -- the son of Linda Thompson and Caitlyn Jenner -- split up with his wife Leah in September 2018 after 14 years as a couple and six years of marriage.

The pair performed together as the indie pop duo Brandon & Leah, and share a daughter, Eva.