Sorry, I have personal reasons that I don't find it funny but I also know you had no idea.
Open marriage is a death sentence in these circumstances. Might as well file for D and just move on. I think if you've been giving and giving, like with the cruises and all, then you might benefit from "Married Man Sex Life Primer". If all else is well in the M except for the amount of sex I think that can help. I was told to give it a read and I did...and I started acting that way but things in my R were too bad, I needed to just DB...now I've made things 100 times worse and I'm trying to truly DB.
“People are just as happy as they make up their minds to be.” Abraham Lincoln