This is "Give Me (What I Can't Get Back)" by I Level (1982). Some of the lyrics are:
When we were in school
You had been saving up for me
But I had to keep my cool
I just had to let things be
But now that you have grown
I'm sure you must have known
That the birds and the bees
Do the wrong thing in the trees
So give me, come on and give me girl
Give me what you can't get back
When we were in school
You had been saving up for me
But I had to keep my cool
I just had to let things be
But now that you have grown
I'm sure you must have known
That the birds and the bees
Do the wrong thing in the trees
So give me, come on and give me girl
Give me what you can't get back