Well, what is it about cruising that concens him?
Price? Cruises look expensive but you have to remember that the price indcludes food, lodging, and transportation to the different ports.
Kids on Disney? Not a problem. There will be kids but there are adults only areas and on Disney most people compain that they can’t get their kids to leave the kids activity programs. Access to the characters is also much less crazy.
Getting sea sick. There is movement, but with the size of the ships and the ships are engineered to reduce rolling.
My DW was not sure so we did a 3 day DCL to Nassau just to stick a toe in the water so to speak. She loved it and I find cruising is the most relaxing trips that we have. You can do as much or as little as you want.
I highly recommend at minimum, an ocean view cabin. I won’t book anything but a balcony personally because I absolutely love sleeping with the door open and listening to the waves, and just chilling on the balcony.
Do not get a couples massage. They are extremely addictive. We did the couples choice last DCL cruise which consisted of a foot wash, hot tub on the balcony, couples massage, then time on the balcony with tea and fruit on the chase lounge. Yeah it was EXPENSIVE but we enjoyed every minute of it! (We get one or two massages EVERY cruise.)
Oh, and welcome to Mouse Buzz!