Well it's taken me a day to write this as I was quite baffled as what to do. I received an email yesterday from our MC that we had booked asking me to call him urgently.
I did so and the conversation went like this... my friend has asked me to MC his wedding day and it happens to be the same day as yours and I was wondering if I could find you another MC to MC your wedding. The friend had apparently asked him to ask the bride to see whether I would let him go. I was kind of gob smacked and upset at the same time, as I didn't want to say no you can't MC your friends wedding but then again this man is a professional and we'd already paid a deposit.