'Big Brother' Couple Jess and Cody Are Engaged -- Watch Him Pop the Question!

The 'Big Brother' and 'Amazing Race' alums had been talking engagement for months.

Jessica Graf got her wish.

When asked by ET in January whether she wanted to get engaged to boyfriend Cody Nickson, she didn't hesitate.

“Of course I [want to be engaged soon],” she told ET. “That's not a question. He knows that.”

Nickson at the time responded that if it happened, he wanted it to be a complete surprise.

Well, Nickson followed through with that on Tuesday, ambushing his "true love" reality star partner at the top of Runyon Canyon Park in Los Angeles with a gargantuan rock of an engagement ring. He posted it all on Instagram on Thursday, from his breathless run to the top of the park, to the kiss, hug and, of course, kneeling down to pop the question.

That was followed by some long, deep hugs and kisses. Graf can be seen wiping away tears at the end of the video.

"Did she say yes, though?" an observer asks in the video, laughing.

"She said yes," Nickson responded.

"I said yes! ?," Graf confirmed on Instagram. "On Tuesday, February 13th my best friend asked me to marry him. He’s made my dreams come true every day since we met! I love you + there’s no one else in the world for me. You’re my person and I thank God for you coming into my life!"

The newly engaged couple owe their relationship to reality TV. They met on season 19 of Big Brother, fell in love and then turned around and began filming season 30 of The Amazing Race a week after the first show ended. The couple has said that the shows have strengthened their relationship, leading up to growing questions about a possible engagement.

It's clear that that those questions were on Nickson's mind, particularly given how much planning appears to have gone into the selection of that huge engagement ring.

“Cody worked directly with Joey Hamra of Hamra Diamonds in NYC to create the perfect ring he envisioned for Jessica,” a source exclusively tells ET. “He [Cody] was extremely particular about the diamond, cut, setting  and all the details to handcraft the ultimate engagement ring for his love."

The source added, “He’s been working on the ring with Joey for months and waited for the perfect time to pop the question.”

Watch the couple take on The Amazing Race in Iceland in the video below.