1:21 PM PT -- Samantha Cope tells TMZ … "As a mother who values her daughter above all else, I find these false accusations deeply troubling. I am confident that the truth is known to me, to Joey, and to God."

"I am choosing to put my focus on healing, caring for my daughter, and processing the loss of my marriage and my family."

Joey Lawrence is clearing up rumors about his alleged affair, saying he and Melina Alves never hooked up on set of their Hallmark movie ... and he's diving deeper into why his marriage ended.

The actor shared a statement on his Instagram mere moments ago ... telling fans he and Alves -- a woman whose husband accused the two of having an affair -- didn't have a physical relationship while working on the movie "Socked In For Christmas," as some have speculated.

JL says the two certainly shared a bond, but it was based only on shared experiences and mutual understanding ... and, definitely not physical intimacy.

Lawrence then launches into a deeper description of his marriage ... saying his union with his wife of two years, Samantha Cope, was riddled with issues since the beginning -- and it was beyond saving, despite his best intentions.

One of the biggest difficulties ... Joey says he thinks his two children from his previous marriage would never be accepted by Samantha -- a significant contributor to their relationship breaking down.

Joey's post comes a day after Melina Alves put out her own. As we told you, the screenwriter took to her IG to deny hooking up with Joey on set ... though she admitted their relationship was "a meaningful friendship that developed naturally."

Alves also said she and her ex-husband have been estranged since 2023 -- a claim sources close to Edward Rider call BS  -- and she has a temporary restraining order against him ... which Ed believes will be thrown out after the hearing next month.

As for Joey and Samantha ... they're moving through divorce proceedings now -- and, Cope's fighting tooth and nail for full custody of their daughter, Dylan.