I’m loose and light and a little sleepy from my second Corona and a blossoming sunburn. Sure, I say, why not, thinking all the while: If any other 27-year-old lesbians could use a self-esteem boost, all they need to do, clearly, is get themselves on an Olivia cruise. I had only a vague idea of what to expect when I boarded the Celebrity Summit in April for a weeklong excursion to the Caribbean.