About the wifes tennis coach!!

Fax form husband to wife.......
To my dear wife:
You will surely understand that I have certain needs that you with your 54 years can no longer satisfy. I am very happy with you and value you as a good wife. therefore, after reading this fax, I hope you will not wrongly interpret the fact that I will be spending the evening with my 18 year old secretary in the Chevron Hotel. Please don't be perturbed. I shall be back home before midnight."

When the man came home, he found the following letter on the dining-room table :

My Dear Husband: I received your fax and thank you for your honesty. I would like to take this opportunity to remind you that you are also 54 years old. At the same time I would like to inform you that while you read this, I will be in the Hilton Hotel with Michael, my tennis coach, who like your secretary is also 18 years old. As a successful businessman and with your excellent knowledge of maths,you will understand that we are in the same situation ... although with one small difference : 18 goes into 54 more often than 54 into 18 .... and therefore I won't be back before lunchtime tomorrow !
A big kiss from your wife, who really understands you ..."