I bet it is hot hearing them fantasize about how they'd use your wife, not realizing who she is with you right there. I did something similar once, leaving some pix of my wife in lingerie on my desktop while I had to be out of the office for a couple of hours. I'm not sure who or how many saw...
That's pretty bold, having your nude wife as a screensaver! I'm assuming you either don't have an IT dept, or that YOU are the company IT guy? Also guessing its a smaller office, not some big corporate place. Either way, super hot!