I'm a sheep and he's a dog

It means that you two need to make effort to keep a long-lasting relationship. Usually, when this pairing consists of a Dog man and a Sheep woman, he will consider her undependable and frivolous. He also has a desire to "save" her. She will admire his idealism and high standards... at first. She will quickly reveal herself as unsalvageable and he will be intolerant. His anxieties and unsocial behavior will become a chore for her. Her emotional needs will tax him terribly.