Not being on your bike doesn't make you a bad person, we all know that's not what biking's about. Sometimes the bike has to sit a few out in lieu of the hot cowboy. Hey, the bike has no feelings and will wait however long you need it too, the cowboy maybe not so much. At least you're still excercising (and getting thumbs up from the horse) and sharing one of your passions with someone.
As for trading in your mtb for a road, that's your decision. Remember though, you can ride your mtb on the road but you can't ride a road bike on the trail.
Life is for enjoying, not feeling guilty when you aren't doing anything wrong- especially if it's fun and with a rovin' work of art!
(Awhile ago it was Agility, tracking, obedience, a tiny bit of herding, Belgian Tervuren and Malinut, er, Malinois, my now senior citizens)
I used to have an open mind but my brains kept falling out.