There is a simple way to solve this problem
Caesars Atlantic City has come up with the following solution :
Family hours: 8am to 1pm
Adult hours: 1pm to 6pm
Though, IIRC, there is also an adults only pool @ Mandalay Bay, which might have been an option instead of the 'frat party' FS pool area.
Since it seems that you paid an average of just about $117/per night @ the FS (^^), I'm guessing that these 'rock bottom' rates are probably taking away a little bit of the 'posh' FS factor @ this property, as evidenced by the pool guests.