Before she met me is a blackly comic tale according to the publisher's blurb. To be honest I just found it to be a piece of misogynistic nastiness that left an unpleasant taste in the mouth. The topic of sexual jealousy could have been a really good theme for a novel. I suspect most of us have experienced it at some time or another; and even though you may be confident that his/her past is in his/her past, it could, given the right conditions become overwhelming. It could make (in the fictional world) for a great crime novel, or even be ripe ground for black comedy (I can imagine a David Lodge or a Tom Sharp doing a brilliant job of it), but Graham was such a horrid character, I'm just surprised that he even managed to survive his first marriage.
It's the first Julian Barnes novel I've ever read. I'm willing to give him another go as I've been reassured that some of his other novels are excellent, but Before she met me is not a book I would choose to read again.