Just Like Yoga
Unlike humans, dogs do not only stretch after waking up. They do this for their muscles like we do, but they also show affection and love this way. When you arrive home and catch your pet stretching, it does not mean that they just finished a nap. No, they want to let you know that they are glad to see you.
Exposing Their Belly
A dog that shows you their belly is one that respects you and shows submission. It might also mean that they want to play. The best way to respond to this behavior is by rubbing their belly. If this happens often enough, they will do it again and again. On the other hand, they also show such behavior when another animal attacks them.