...補充： Good thinking, Wayne! But I think "piss down" is a slang. It may not be appropriate to use it here. :)
...and it was really (let my boss down) and pissed him off. 這真的讓我老闆失望而且...更正XD! and it really (let my boss down) and pissed him off. 把was拿掉，我筆誤了...
... time I was late for work, and it really let my boss down and pissed him off. Why was I late for work? Actually...