Plus, how we secured that cameo from two OG franchise stars, and how the Super Mario Bros. theme was once part of Anderson's jazz scat.

As the costars promoted crime-spoof sequel The Naked Gun, they have been "enjoying each other's company," continued the source. Neeson and Anderson have exchanged sweet kisses on the cheek on red carpets, and recently puckered up to apply Anderson's Sonsie lip balm while on Watch What Happens Live with Andy Cohen.

Pamela Anderson and Liam Neeson have been turning heads with their flirty red carpet moments—but is it real romance or just promo magic? A body language expert weighs in, and what he says might surprise you.