An executive goes to see his doctor, complaining of feeling worn out all the time due to his long working hours. The doctor asks him a few questions about his lifestyle.

Doc: "So, do you and your wife have an active sex-life?"

Exec: "Yes, doc, twice a day, once in the morning before I go to work and again last thing at night."

Doc: "Hmm, and any other love interests?"

Exec: "Actually, my secretary, twice a day, once at eleven o'clock when she brings my mid-morning coffee and again at four o'clock when she brings my afternoon tea."

Doc: "Hhhhmmmmm, and so you make love a total of four times a day?!"

Exec: "Actually, I also see my mistress twice a day, at lunch-time and we make love, and I pop round to see her on my way home from work and we make love then, too."

Doc: "My God, man, no wonder you're always feeling exhausted! You really must take matters in hand!"

Exec: "But I do, doc, twice a day..."