Carnival is pretty good at making sure kids are not in the casino. You can walk through the casino with a child in tow but if you stop you will be told to take them out. You would not be able to stop for 10 minutes. There are slot machines on the outside edges of the casinos where you or you hubby could play and the child and other parent could watch from the hallway but there isn't a whole lot of fun in doing that.
Of course, that doesn't mean people obey the rules. Too many times I have seen parents ignoring the casino hosts announcements about "no children being allowed in the casino" when they are clearly being aimed at them.
If you want to play in the casino together, you are going to have to do it while your children are at Camp Carnival.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013