Letter asking for repayment of a loan to a friend

Dear Andrew

I waited as long as possible to write this letter. I chose to write this upon the hope that you will fulfill your promise of repaying the money that my wife loaned to you this past year.

I know you asked for the money as a friend, and my wife gave you the loan because you are a friend of mine. Now that the money has yet to be repaid hangs over us like a dark cloud of doubt.

I have no further course of action than to ask that the money be sent to us by return mail by the end of this month.

Sincerely
Mario Push