Caitlyn injected some levity into an emotional conversation with Kris, wondering aloud to her ex-spouse, "Maybe at some point we'll renew our vows."
After a long pause, Kris, 60, simply said, "What? Do I get another diamond?"
Caitlyn, 66, laughed, telling Kris, "I don't want you to get your hopes up. I'll need a diamond too."
The moment came at the end of a lengthy conversation where the pair reflected on their marriage – specifically the last few years before announcing their split in October 2013 and Caitlyn's transition.
"I think over the last couple of years, you were frustrated with me. I was frustrated with myself," said Caitlyn. "I just want to apologize for a lot of the times the way I acted. It didn't have to be that way. I think going forward from here, I would always want you in my life."
Caitlyn went on to say that although she now has a "very different" relationship with Kris, she hoped it "can be a really good relationship."
Kris agreed and said she was moved by the words.
"That's everything. That's why I'm here. I came to check up on you. I still love you, and the kids still adore you," said Kris.
I Am Cait airs Sundays (9 p.m. ET) on E!