I'm always slightly uncomfortable talking to a married woman when her husband isn't around so I created a checklist for myself.

1. Stand at least 72 inches apart so in the event of an earthquake neither party will land on top of the other and look incriminating.

2. Display slight irritation or boredom no matter how interesting the conversation is, even if she's talking about football, war stories, or comic books. Believe me, looking interested = "looking interested".

3. End every sentence with "...and I'm totally not hitting on you."

Examples:
"What did you think of the pastor's sermon?... and I'm totally not hitting on you."
"Your kid behaved wonderfully in Sunday school this morning... and I'm totally not hitting on you."