An old lady wants a better sex life

An old lady goes to the doctor because she wants a better sex life with her husband. The doctor prescribes Viagra for him, when she says:

"No way, doctor. My husband doesn't even take aspirines. He would never take Viagra. He's just too proud".

"Well, in that case, just hide one pill in his sandwich. Come here next week and tell me how it went".

The next week, the old lady sees the doctor again.

"Oh no doctor, IT WAS HORRIBLE! HORRIBLE!"

"But what happened? Did you follow my instructions?"

"Yes. I hid the pill in his sandwich and it worked immediately. He stood up and unzipped his pants, bent me over the table and made love to me in the wildest and craziest way. It was HORRIBLE!! Horrible!!"

"Wow but why was it so horrible? Wasn't the sex good?"

"No, doctor. It was the best sex I had in 20 years. It's just that I will never be able to enter a McDonald's again".