A young man goes into a pharmacy and tells the pharmacist...

-Hi, can you give me a condom? My girlfriend invited me to dinner tonight, and I think she's expecting something from me. 

The pharmacist gives him the condom, and before leaving, the guy turns and says: -Give me another one, because my girlfriend's sister is really cute too, and she's always crossing her legs provocatively when she sees me, and I think she's expecting something from me too. 

The pharmacist gives him a second condom and before leaving, the guy turns and asks again: 

-Come to think of it, give me another one, because my girlfriend's mom still looks pretty good, and when she sees me, she's always making suggestive remarks... And since she has invited me to dinner, I think she's expecting something from me. 

At dinner, the guy is sitting with his girlfriend to his left, the sister to his right, and the mother in front of him. 

The father arrives and the young man immediately lowers his head to pray: -Lord, I bless this dinner, thank you for what you have given us... 

After a minute the boy is still praying: -Thank you, Lord, for your generosity... 

Ten minutes pass and the boy prays again, always with his head down. 

The family is surprised, and the girlfriend even more than the others. 

She approaches the guy and whispers in his ear: 

-I didn't know that you were so religious. 

And he answers: -I didn't know that your father was a pharmacist!