Pamela Anderson and Liam Neeson had fans eating up their flirty press tour, but behind the scenes, it was all a PR "bake-off" ... TMZ has learned.

Sources with direct knowledge tell TMZ ... the whole "Pam + Liam" love fest was cooked up by their PR teams and Paramount -- while "The Naked Gun" was still filming in Spring 2024.

In fact, we`re told Pamela and Liam didn`t even see each other from the time cameras stopped rolling in June 2024 until the press tour launched more than a year later, in July 2025.

A big slice of the stunt involved Pamela claiming she was baking muffins and sourdough bread for Liam -- something he even played along with in interviews leading up to the premiere. It makes us now assume that was also part of the strategy ... pure role-play PR, not reality.

Our sources also say Pam and Liam have never had one-on-one dinners. Whenever they did break bread, assistants were at the table ... strictly biz, zero romance.

We reached out to both actors` reps, but so far, no word back.

So forget the love story ... this was always just a recipe to put asses in movie theater seats, and we gotta say it worked!

`Naked` grossed over $89 million worldwide, on a $42 million budget. Sooo ... suckers!