Emotional Whore.

A person who does not know how to be alone and that is why they are always in a relationship. A promiscuous person with emotions, who falls in love every day. Each of your relationships is the final one, even if you have just met your partner.
Someone like Ted Mosby.

-He told me I love you on the first date. Must be a emotional Whore.
-It's his fifth everlasting love this month, it's an emotional whore