Just spotted this now. I was wondering if you might have noticed Sparky's eyesight might not be up to par or if not his eyesight then maybe his hearing is fading a bit? I know my cousin's Bichon got cataracts and later the hearing was going and her dog got clingy the same way you're describing Sparky's behaviour. I think maybe they feel a bit lost if that happens so you become their security. If he doesn't see too well or hear too well he wants to be near you, his anchor in a storm

I've also heard of Cognitive Dysfunction .....it's a form of Alzheimer's in dogs that causes the same symptoms that you describe.....again you become his anchor in the storm. I guess all you can do is love him and and make him feel secure by being there for him....what a nice compliment he's paying you