Yeah, I've got to say you need to kill this behavior now. Mac has to know in no uncertain terms that the crate is Eowyn's and it is her safe place. And you certainly don't want her to dislike her crate, so it's got to be Mac who gets trained. It's cute once, but after that, he's probably enjoying getting her to react and play with him.

Maybe teach her to tug with a toy, and Mac can play that game instead?

"Im in yr crate, dissin' yr dog."