'Big Brother' Star Vanessa Rousso -- Me And My Girlfriend Are Getting Married!!

"Big Brother" star Vanessa Rousso is headed down the aisle with her longtime GF, Mel.

Mel popped the question Thursday night in their hotel room before the "Big Brother" season 17 wrap party in West Hollywood.

Vanessa didn't win the $500k on "Big Brother"... she got eliminated in the final week, but she's not exactly hurting for cash. She's considered one of the top female pro poker players in the world.

She announced the engagement onstage at the party. They've been dating for years.

All bets are now off.