No wild office sex adventures on my side, however early on in my career I fucked up a tender quote that I prepared, I miscalculated the total price of hardware by $40,000. I only realized it after the deal was sealed and we couldn't change the price. The client was also surprised about the low price but they kept silent. Even though i was real close to My boss he was furious and didn't talk to me for a week. I pretty much assumed I'll be fired as the firm had to take a $40K loss on the deal.

Eventually my boss forgave me and I wasn't fired, I made up for the loss in future deals so things got sorted out eventually.