Mo is right, it's about 4 hours, by the time you figure in traffic, etc.
Lee's is a very reputable company. You could also contact Couples OR and see if they are taking anyone to Negril and try and catch the bus there.
I was at CSA and loved it! Negril was beautiful, but we had no problem with nudity. Couples doesn't allow nudity on public areas of the property. In Negril all beaches are public, be we never saw anything other than a topless woman, and not many at that. I meant to walk down to CN, but never did. We were having too much fun where we were.
COR will be open by the time your honeymoon rolls around, so you could stay there if you just wanted a change of scenery.
If you have any questions about Couples, please feel free to PM me. I'll be more than happy to help anyway I can!