How would you react if you picked up your to-go order from a restaurant only to find the word "fuck" written on the inside of one of the lids?

Someone at my restaurant jokingly wrote the word “fuck” inside a lid for a to-go “squat cup” (a little bowl) and unfortunately the lid made it into a customer’s bag and on to his hotel room. Personally, I think it’s unprofessional, yet hilarious. The guy was pissed and called the restaurant ranting and raving. The managers had all the employees write the word “fuck” to compare with the lid (equally hilarious), but still haven’t found the offender.

So, if you were the customer, would you laugh or be offended and raise hell?