It's wrong to lie to someone about having a partner.
Hank, a married man, is in a bar when a woman begins to hit on him.
Hank wants to talk to the woman.
Hank tells the woman that he's married, but that they can talk if she wants.
Hank says that he's not married and talks with the woman.
The woman chats a bit with Hank in a friendly way.
Hank commits adultery with the woman.