Only have eyes for somebody - Idioms by The Free Dictionary
only have eyes for somebody
only have eyes for (one)
To be romantically interested in or devoted to only one person. I know you're a little worried about me being around all of these beautiful women, but I only have eyes for you, my darling. You can tell by the way she looks at him that Beth only has eyes for Trent.
only have eyes for somebody,
have eyes only for somebody be interested in, or in love with a particular person and nobody else: John tried to get Helen to go out with him, but she only had eyes for Chris.