Wanting a divorce

A local lawyer was sitting in his office the other morning when in walked a beautiful young lady.

Without any preliminaries she said she wanted a divorce.

"On what grounds?" asked the lawyer.

"I don't think he is faithful to me" she replied.

"And what makes you think he isn't faithful?" asked the lawyer.

"Well" replied the young lady

Spoiler:

"I don't think he is the father of my child".