Jenna Dewan is engaged to Steve Kazee.

Steve Kazee and Jenna Dewan

Steve Kazee and Jenna Dewan

The 'Flirty Dancing' host has revealed she and her partner - who are expecting their first child together - have taken their relationship to the next level as she looked forward to their "lifetime" together.

Sharing what appears to be a professional snap of the pair kissing as she shows off her engagement ring on Instagram, she wrote: "A lifetime to love and grow with you... you have my heart."

Her husband-to-be shared the same touching photo on his own social media profile, he posted some lyrics from the Water Liars song 'Let It Breathe'.

He wrote: "When you wake in the morning I will kiss your face with a smile no one has ever seen.

"When you wake in the morning I will kiss your eyes and say it's you I have loved all these years."

Jenna recently revealed her and ex-husband Channing Tatum's six-year-old daughter Everly is "preparing" herself for sleepless nights when her half-sibling is born.

The 39-year-old actress said: "She just said to me this morning, 'I'm preparing myself for that baby to cry all the time.'

"It was so adult and she asked me if the baby cried in the night if she could get out of her bed and go sing the baby song. And I was like, that is so sweet."

And her 43-year-old partner Steve previously said he was "nervous" about becoming a father, but was "in awe" of the fact that there's "life growing" inside of Jenna.

The Tony Award winner said: "I'm nervous as can be, but I'm trying to just be calm about it and know that we've been doing this for billions of years, millions of years at least, so we're going to be OK.

"There's no way to even describe how excited you are at this moment, but we're beyond. We're very happy. It's an incredible experience. I'm, like, every day just in awe of the fact that there's a life growing inside of this human being that I love so much."