This joke contains adult humor, the two adult words are censored on the forum so sorry if it sounds a bit weird.
Also apologies because I just heard this joke in a pub and I'm slightly tipsy so this might not have the best English!
A man walks into a bar and asks for a rum and coke, the barman reaches behind the bar and sits an apple in front of the man. "I asked for a rum and coke" said the man, "Give it a bite " replied the barman, so the man bites into it and says "That tastes like rum!". The barman looks at the man and says "Now turn it around", so the man turns it around and takes a bite from the other side "This tastes like coke!" he exclaims. The barman smiles and turns to the next guy at the counter.
"I'd like a gin and tonic" says the next man, again the barman reaches behind the bar and sits another apple in front of this guy. He gives the barman a skeptical look and then takes a bite of the apple, "This tastes like gin!" says the man in shock. "Now try the other side" replies the barman, the guy turns it around and takes a bite of the other side, "Wow, and this tastes like tonic!" he shouts. At this another man comes into the bar, walks up and sits on a stool.
The first two men turn and say "This guy is a genius, he can give you an apple that tastes like anything!". The third guy sits there for a couple of minutes wondering what he should ask for, eventually he says "Do you happen to have an apple that tastes like ######?". The barman rummages around behind the bar for a minute and pulls out an apple, the man takes a bite of it then spits it out and shouts "THIS TASTES LIKE CRAP!", the barman looks at him and says "Turn it around."