The rugby player put his arm around his beau who covered her growing bump in a long coat at the Eddie The Eagle premiere on Thursday evening.
Kristina and Ben are expecting a baby together
The professional dancer first announced she would be welcoming a baby when she appeared on Celebrity Big Brother, telling her fellow housemates: "I found out that my boyfriend and I are going to have a little one."
The mum-to-be revealed she would be leaving Strictly Come Dancing to prepare for motherhood. "It's a bittersweet situation. I was on Strictly for eight years and I always loved the dancing side of it, but I feel relieved because I wasn't happy towards the end.
"I'm also sad because I'm going to miss everyone. I will always be grateful for the fantastic opportunity that Strictly gave me to be part of such a brilliant show."
Kristina first announced her pregnancy on Celebrity Big Brother
Of her decision to bid farewell to the BBC show, she told HELLO!, "Strictly takes a toll on your life," as she reveals that she almost quit the show last year and signed her contract two weeks later than the other dancers.
"It's very intense and it's worth it if you feel like you are fulfilling yourself as an artist… those moments when you feel you have done great choreography to a great song and a good concept. But I feel some of that creativity was being taken out of my hands."
Kristina is looking forward to having her first child and she revealed her mum is even more excited. "It was a surprise but I am obviously delighted," she said. "My mother was with me over Christmas and when we found out she put her arms around me and she cried with joy. It is her lifelong dream for me to have a child and it was lovely to see her so happy."