If you truly love him, tell him straight up, you'll be there for him if it doesn't work out with new girl. Plus if it's true love just remind yourself how good you most be to him and how happy you are by not being jealous. Whatever you do don't make his new girl jealous either because you won't be able to be around him as much. Good luck, I married into love and then she became my best friend. I would have rather had what you have now then love.