Old tattoos or unwished can be covered with others.
New tattoos can't have lighter colour or smaller than old tattoos, so cover of tattoo is limited.

A way simple and cheaper could be same design but with darker colour.
When you want to remove old tattoo or unwished the best way would be to go to a tattoo artist he will tell you wich is the best design to cover your tattoo.

If your old boyfriend or girlfriend betrays you then no need to worry about the tattoo which you had inked yourself with to show your love towards him/her.

You can simply wrap up your those bad memories with new tattoo over it.