The tattoo model surprised motorcycle customiser Jesse with the design of his face taken from a childhood school photo.
In an episode of her TV show 'LA Ink', she is seen saying: "I'm getting his face tattooed on me and I have no idea how he's going to react."
Jesse, 42, then arrives at her Los Angeles tattoo shop, but seems nervous about his surprise, joking, "I feel like I'm in court," when she teases him about it without telling him what it is.
When she reveals the etching which has been inked on the left side of her body, Jesse's reacts by saying "you're crazy," but tells her he loves it, and "I love you".
Kat later admits she wasn't too sure about his reaction, telling him: "I thought you were going to tell me you were breaking up with me."
The couple confirmed they were calling off their engagement earlier this week, with Jesse citing the long distance between them as "too much," Kat lives in Los Angeles, while he is committed to staying in Austin, Texas, for his children Chandler, 16, Jesse Jr., 17, and seven-year-old Sunny.
He said: "I'm so sad because I really love her. The distance between us was just too much."
Writing on her twitter page, Kat confirmed the separation, saying: "I am no longer w Jesse, and out of respect for him, his family and myself, thats all the info I'd like to share. Thanks for respecting that. (sic)"
Jesse - who was married to Oscar-winning actress Sandra Bullock for five years until 2010 - got engaged to Kat in January and they had been planning their wedding to mark their one-year anniversary later this summer.