One you slip around with

I had the key to heaven when we married
And for a while I brought you happiness
But now your love for me is dead and buried
And every night you share another's kiss
And I'd rather be the one you slip around with
And be the one who's dream of love is gone
I'd rather be the one you spend your time with
Than be the one at home all alone
Deep down inside I know that I should leave you
How many tears was fallen before I learn
I think of many ways that I could grieve you and yet I'm always here when you return
And I'd rather be the one...