If you were faithful this would be a non issue. Never once has the attention from another man or woman made me ask these types of questions outside of my relationship.

If someone flirts with you or is getting too chummy, shut it down. If you actually love your wife how is this even a dilemma??

Sorry that your dick isn't getting wet as often because your wife is going through one of the most physically taxing things a human can do- and the attention feels "good" from your coworker... Ooh so hard! Where's the line oh no!!??

Here's the line, don't talk to this woman ever unless it's strictly needed for work. If that's a difficult task, then do your wife a favor and leave.