Kissy, kissy, Kirstie!

The most talked-part of Kirstie Alley's second Dancing with the Stars routine with partner Maksim Chmerkovskiy might not be part of the choreography.

At the conclusion of the duo's quick step routine during Monday's show, Chmerkovskiy clutched Alley, 60, for a deep dip -- and they both leaned in for a wet kiss!

After the routine, Alley told host Brooke Burke that the lip-lock wasn't planned. "It was spotaneous," the actress confessed, giggling. "I wasn't gonna do it!"

The on-the-fly PDA worked for the judges. "The connection between you and Maks? That was unstoppable!" Carrie Ann Inaba gushed of the couple. "You are so in your element! I love watching you dance. It was faaaabulous"

But in rehearsals, Alley struggled with an old foe: Her weight. "I've never been confident with where I am [no matter how much or little I weighed,]" she admitted as she she fought to master the quick choreography. "You have to find a [weight] where [you feel], 'This is good.' I don't want to be dead when I do that!"

(Alley says she currently has about 40 pounds left to lose, and is dropping about 5 per week thanks to her sweaty DWTS work.)

She even asked Chmerkovskiy whether "skinny girls" encounter the same difficulty mastering the steps.

"Don't worry about your weight," judge Bruno Tonioli urged the star after her dance. "You have talent. [Just] be yourself!"

The duo nabbed a respectable 20 points for the night.

Tell Us: Do you think they have good chemistry?