Clique, I know. I just like the idea of it. I think it really brings meaning to the phrase, "wearing your heart on your sleeve"
Everyone is born with an one-of-a-kind tattoo somewhere on their body. I don't really know where. Maybe right above their collarbone, or on their ankle or something.
Every time you fall in love, you get that person's tattoo. it can be anywhere. If it happens to be your soulmate, it would be right over your heart. It would only be there if it was your soulmate.
People who fall in love easily would have them all over their body, except for one place. Over their heart (unless they already had fallen in love with their soulmate of course)
Aromantics would only have their own tattoos
People who have love affairs trying to cover it up from their partner
Elderly people pointing at each of their tattoos, and telling the stories of the people they are about
Little kids giggling and daydreaming about their future tattoos while looking at their original tattoos
People trying to deface tattoos of lovers that were abusive or cheated on them. except for the fact that they can never go away