only have eyes for someone
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 someoneor
have eyes only for someone
If you only have eyes for one person, they are the only person that you are interested in romantically. The 26-year-old model is adored by thousands but only has eyes for one man — her husband. They attracted lots of attention but they had eyes only for each other.