As a buyer, when you are walking through a home, keep in mind that the seller might be listening. 

These days, there are plenty of ways that a seller could be monitoring their home, with a security camera, or other recording device that could allow them to hear every word you are saying while you are in their house.

So.....

[1]  Don't insult their house.  It won't help during negotiations.

[2]  Don't discuss negotiations.  You might be revealing your strategy.

By the way, sellers, you'll need to disclose if there is a recording device in your home.  There is a field in our local MLS specifically for this disclosure.