nose wide open
The term is used to say a person, most usually a male, is crazy in love or lust over a girl, will focus total attention on her, ignoring his friends; maybe a hint that she is exploiting him.
i never see him now that he's smitten with his new girlfriend. he'll do anything for her; she's got his nose wide open.
nose wide open
It means like a dog in heat, a guy can smell that the female is in heat. He has the hots for you!
All that nasty stuff girl does for him, got his "nose wide open"