I’ve probably been on 20 gay cruises over the years. I know it will be different on a straight one but a lot of action takes place in the steam and sauna rooms of the ship.
Typically we do concierge class or a suite. I’m not sure how that translates to Carnival. You might look into a pass to the gym which would include steam room and sauna.
On gay cruises it’s common to see guys making out, oral sex and all out fucking in these private areas. I’ve never seen anyone complain about this activity or leave in disgust or pissed off. I’m not sure that a bunch of straight guys would be so nonplussed.
Also, there are balconies at the back of the ship that become more adult oriented. I’ve found that nude sunbathing is allowed though discretion is required for anything more. In the dark of the evening much more takes place on these rear balconies.
Since children may be present on your cruise things can be difficult. Children are not an obstacle we have to overcome.
Good luck