Very interesting question and responses! DH and I ride together sometimes, but he is a stronger rider than me but I love riding more, which causes some tension (mostly my issue). We ride together only for a "few miles to an ice cream stand or breakfast spot, and then home", kind of rides- recreational rides, not fitness.

When riding with him, I ride my roadyish hybrid and put him on my mountain bike to give him a handicap, so to speak. After him saying bike speed and power are all about the rider not the bike, we did some trials of my hybrid against his super nice roadie, and he had to back WAY down on that statement!

I love mountain biking, though I don't get out as often as I like. He has NO interest in it and finds it very hard core, which I find amusing.