Idk how the laws are at all between adults but I mean getting a video of two people fucking regardless of context is probably an issue if there's no consent given lol probably nothing to be done with the one instance but like you can't just constantly send dick pics to someone lmao it would eventually qualify as harassment. And she probably wouldn't have the luxury of simply blocking him due to their kids being involved, some contact or availability would have to he maintained for them.
But yeah all depends on of its true, but if it is...I'm not sure if sending videos of yourself fucking someone to anyone is or should be legal without consent