I agree. You should try to make the bird unlearn it, or you could teach it something similar, but not dirty. You can't react in any way when it says the words, because in a parrot's mind, any reaction is a good reaction. No hitting, no yelling, no shushing. Don't even move at all. Just talk on like the bird didn't say it at all. Also, to everyone saying "Kill it," a parrot with the capacity to learn to speak multiple phrases clearly in a brief period of time, such as when OP was on holiday, is not going to be a cheap bird. Only the larger birds tend to be clear speakers and have the capacity to learn that quickly. Smaller birds, from budgies to conures, can speak, but it is not clear and takes them quite a while to learn. If it's clear enough to worry about, it's probably a valuable bird. Well, it was, but learning to cuss devalues parrots quite a bit. As a parrot owner, I know how angry I'd be. Just take some time with the bird though, OP, and you can probably fix the situation.

Expensive = delicious. Eat it.