She responds totally differently when she sees him.
She trills at me, but when she sees him she purrs loudly and does her dramatic 'flop on side' thing.
When my daughter and s-i-l were just dating, her cat, who had lived with her for YEARS, fell madly in love with my s-i-l and no, he did NOT live with my daughter. And once they were married, that cat was HIS!