I completely agree with cereta re: the fact that radical acceptance would be a very useful skill here. (It's also one that until you've gone through DBT training sounds both too simple and completely impossible, and it took me until two weeks into my own partial hospital program as a patient to actually be able to understand/employ it properly!)

But I'm also stuck on the fact that the ex said she loves LW, and he's conflating that with being in love with.

I love my best friend more than anyone in the world. She's been there for me longer than my husband and we have more common interests than my husband and I do, so if I had to somehow arbitrarily quantify love, I love her more than I love my husband (though they get along great and this is not a thing that should ever matter) ... however, I am not in love with my BFF and do not want a relationship with her. I am in love with my husband and am happily married to him! The ex probably still has a lot of love for LW, and maybe if he stopped being super creepy they could be very good friends once they've both had time to grieve. But it's not the kind of love she wants to have in a relationship.