My Treasure said to me the other day that he likes to be bound, wear his collar, as well as go around leashed to me, because it gives him a satisfactory feeling of being owned. He said that he has never been very social, not much of a "joiner." Being bound, collared and leashed makes him like he belongs (at least in our alternate universe).
Of course, he belongs to me, but I have always been careful to protect him from the vanilla men we encounter (women do not seem to find it odd that I have a submissive) by just requiring the collar. Evidently I do not need to protect him. He likes it. He told me that being collared and leashed in public, and bound in private (and sometimes in public!) tells the world that I have chosen him, that he is capable of satisfying a strong, outgoing and successful woman. So, his collar and leash are his way of showing off!
The important thing, though, is that it makes him feel safe, cared for and that I am thinking of him. That I am showing the world that "he is Mine." I am showing the world that he is someone I care about and care for. So I am showing off, too. Maybe I will take him for a walk on his leash this evening.