"It was so nice, the unexpected parties are the nicest ones," Guardiola, who takes his team to Newcastle on Friday, said at a news conference on Thursday.
"If you organise a big one they can be boring. But we came here [to the CFA] and we hugged a lot and remembered how good it was. We had some pizza and that was the best moment of the night.
"I was not in perfect conditions to decide [which pizza]. In England, the party is always just alcohol and I don't understand why."
Kevin De Bruyne missed the league defeat to Chelsea on Saturday after picking up an injury in training and he is likely to miss the trip to St James' Park but Guardiola is hopeful he will be available for the final in Porto in two weeks' time.
"He is still injured," Guardiola added. "He's getting better. When he's fit he will come to training. The guys who are 100% fit will have the chance to play the final. We'll see how the team and the players are and give them a chance to play the last games of the season."