main squeeze

One's primary romantic partner or sweetheart.

1.  One's boss, the highest authority, an important person. For example, Who's the main squeeze in this company? This slangy term was first recorded in 1896, and the precise allusion is unclear.
2.  One's sweetheart, as in Nancy is his main squeeze. This slangy usage, first recorded in 1970, alludes to the "squeeze" of a hug.