It's a wonderful idea to share such a fun passion with your DH and it would be great for you to have an "in house' quilting buddy... that is IF it would work. It depends on how well you and your hubby rub along while working together or in small areas. Maybe you could give it a try and work out some guidelines together? (such as asking before cutting up stash)
For instance: How do you do together in the kitchen? My DH and I don't share the kitchen very well. He is a wonderful cook and I know I am blessed. But, when cooking together, he tries to take over whatever I am doing and he uses every pan we own and makes a huge mess, while I am a "clean as you go along" type of cook and my slwness drives him crazy. ... I can't imagine sharing my sewing space with him. I'd get upset at the mess. He needs a hobby too, but maybe one that doesn't use the same resources.
Good luck in helping your DH find his passion!