our first house had an abovegrund pool. I never used it because I can't swim and am afraid of water, don't even like the shower on my face.
Rob was gone all the time but friends loved it, they'd come in the front door and straight out the back. we finally sold it.
As noted above Check Your Homeowners Insurance. They are considered an 'attractive nusiance', as in people can and will sneak in and you are responsibe even with fences and signs.
but if you love having a pool go for it, your home your money your priorities!