he sings most of the song but towards the end she responds to him.
The lyrics go something like (male vocalist) "Baby when i call you on the phone...(some words.. not sure..) and you be playing games with my feelings.. dah.. dah dah.. dah dah..(then female vocalist) Boy when i call you on the phone.... and you be playing games with my feelings..." etc etc.
Unfortunately, thats all i know.
It's a pretty slowish track. I would say about early 2000's.