A dog that leans into you is not being clingy for the sake of it. The behaviour has a physical logic behind it: dogs seek pressure against their bodies as a way to regulate their own arousal state. The same mechanism that makes a snug wrap calm an anxious dog at the fireworks is at work when your dog presses its flank against your shins and stays there. It is not random, and it is not simply about love, though the two can overlap.
