“Dancing with the Stars” sudden favorite to win KIRSTIE ALLEY has gone full-out cougar kicking up her heels with a new man who’s only 21 years old!

Kirstie, 60, shocked friends and fans when she recently strolled outside The Colony nightclub in Hollywood hand in hand with hip-hop artist Shancie Boyd, who only recently became old enough to drink.

The odd couple was introduced by Kirstie’s fellow “DWTS” contestant Romeo Miller in March, and sources maintain Kirstie is reveling in the attention he’s heaping on her.

“Kirstie loves going to dance clubs with Shancie and behaves like a giddy college girl around him,” said an insider.

The two have made their May- December romance public by flirting with one another on Twitter.

0On April 3, Kirstie used the social networking site Twitter.com to send Shancie this message: “…Prom King… U really know how to take care of your prom queen…Sweet…Sleep well… Xoxo.”

Then, on May 3, just hours after being spotted exiting The Colony with Kirstie, Shancie tweeted to Kirstie: “Always fun with my prom queen.”

And while it’s unlikely that Kirstie is the size 6 she claims to be, there is no doubt she looks better han she has in years – and now her long-barren love life has suddenly turned hotter.

“She’s been consumed with her kids, her career and her weight problems for the past decade, but now that she’s shed pounds, she’s back on the market,” the insider added.

 Shancie posted the bar bill for his May 3 outing with Kirstie on Facebook – and it came to a whopping $51,231! But it appears the bill was for an entire party of people.

Added the insider: “Kirstie’s not ready for commitment, but she’s having a blast enjoying her new life, her new body and her young new beau.”