Ctrl(CMD on Mac) Shift D will deauthorize your computer
Ctlr(Cmd on Mac) Shift E will deauthorize your device
When authorizing the Nook using ADE it will always use the AdobeID that ADE is authorized to ("Library->Authorize Computer..." will show you the current AdobeID)
You want to get it so that your device and ADE that you used is authorized to the same AdobeID. Note that only one ID can be active at any one time so you have your choice on your nook (and your laptop) of viewing content licensed to your husband AdobeID or to your AdobeID but not both. So I would pick the AdobeID that best suits your situation.