I wouldn't have thought so either, but... on a social media group, someone posted the rules as follows - this is a direct quote - and was apparently confirmed as official policy. I bolded the part that would apply to me.
To clear up the confusion above, the official policy is you can book 2 staterooms, per household, per stateroom on 1 future sailing each.
Examples:
James living at 123 Main Street in the same stateroom as Susie living at 456 second street may book 2 staterooms on 1 future sailing EACH.
James may book his 2 staterooms on the same or different cruise as Susies 2 staterooms.
Susies 2 staterooms MUST be on the same sailing. James 2 staterooms MUST be on the same sailing.
Johnny and Mary both living at 123 Main Street in the same stateroom may book 2 staterooms on 1 future sailing, period. They may not book more than 1 future sailing and/or more than 2 staterooms. Johnny and Mary’s 2 staterooms MUST be on the same sailing.
Mike and Sarah both living at 123 Main Street in 2 different staterooms May book 2 staterooms on 1 future sailing each. Mike may book his 2 rooms on the same or different sailing as Sarah. Mike and Sarah MUST be in different staterooms on the future sailings. Mikes 2 staterooms MUST be on the same sailing. Sarah’s 2 staterooms MUST be on the same sailing.
For all 3 scenarios, the lead guest MUST sail in the 1st of the 2 staterooms. If the lead guest is removed or moved into one of the other staterooms, the discount is removed from that stateroom.
For all 3 scenarios, the guests in the 2nd staterooms DO NOT have to be onboard at time of booking.