damnthatanxiety
*How do you know your friend believes he loves her? Have you discussed him with her? How does she justify his appalling behaviour around other women if she is a feminist? Is she in denial?
Does he actually treat her well and apparently lovingly or is that just her perception?*
I have discussed him with her in the past, more than I'm comfortable with: she loves to talk about him. He has never told her that he loves her. She worships him, I don't think this is an exaggeration, and she "knows he loves her but isn't the kind of person who finds it easy to talk about his feelings".
I can't answer your question about how she justifies it. I have often heard him say appalling things about women I know, and she laughs along with him. When I hear her call herself a feminist, I honestly find it mind-boggling: but she's in so deep with him, I can see she's completely in denial. He is funny and charming and makes it all sound like such a joke.
He does actually treat her well, publicly. She is the only person anywhere whom he treats well. I mean this superficially. He talks her up in public, he gives her extravagant gifts, they kiss and cuddle a lot in public. Most British people (imo) find this a bit undignified: they definitely go further physically in public than anyone else I know - I mean constant touching, pawing, hair-stroking, her sitting on his lap, nothing sexual.
However he has behaved so badly in his job that he's been written about in the press and is under investigation. That is not treating your spouse well. I know quite a bit about him that I have no idea if she knows or not. He is not a good and loving person.
And yes, it is a very strained friendship under these circumstances! I/we no longer wish to see him, so contact with her has dwindled to online only. I keep in touch with her because one day it will all blow up and we have such a long history, I can't not, iyswim.