A "Love Handle" is a cute term given to someone you love such as your friend or significant other.
Love handle: A friendly nickname or moniker. But love handles are a bit more unique and personal than your run of the mill nickname and pertain to the person's interests or appearance. So, something as simple as "Sweetie" would not be recognized as a Love Handle.
Such "Love Handles" can also be used as code when you are talking about a person you like and you don't want other people in the room to know their exact identity.
I gave the guy I like the Love Handle 'Orange Crush' because he's a red head & likes R.E.M, and I like Orange Soda...