I have worn pants and a sweatshirt in Negril in April, on separate occasions. I sometimes wear jeans on the plane but don't ever put them back on, not even for the return flight. I now try to wear something on the plane that I might actually wear again - next trip it will be a pair of fitted jogger capri sweat pant. At the very least, I'll wear them on the flight home, but I can see myself wearing them during the week in the evenings relaxing on the front porch.
Agree with others that some kind of pant is appropriate for church, certain outdoor activities, and nice restaurants/special occasions. I don't think jeans fit the bill for any of those activities, but that's just me.
I say live and learn could be a good attitude here. If your SO is anything like me, once I have something in mind, I need to see it through or I feel uncomfortable. So packing or wearing jeans once might be enough to convince SO to never do it again. Locals wear long pants all the time... so I don't think it's that crazy. Maybe in July!
In any case, have a great trip. It would be fun to bring someone to JA for the first time. I'd love to experience that!
