"Medical Bill" joke

A man was brought to Mercy Hospital, and went in for coronary surgery.
The operation went well, and as the groggy man regained consciousness, he was reassured by a Sister of Mercy waiting by his bed.
"Mr. Smith, you're going to be just fine," the nun said while patting his hand.
"We do have to know, however, how you intend to pay for your stay here. Are you covered by insurance?"
"No, I'm not," the man whispered hoarsely.
"Can you pay in cash?"
"I'm afraid I can't, Sister."
"Do you have any close relatives, then?"
"Just my sister in New Mexico," replied, "but she's a spinster nun."
"Nuns are not spinsters, Mr. Smith," the nun replied. "They are married to God."
"Okay," the man said with a smile, "then bill my brother-in-law."