Alan (played by Trevor Adams) features in "The Wedding Party". He is a hip young man who arrives with his fiancée Jean. Basil constantly appears unamused at the couple's openly flirtatious relationship, to the extremes of believing their hanky-panky is 'dis-gust-ing'.
He tries to separate the couple in different rooms, because they aren't married. They specifically ask for a double bed, but Basil is adamant on giving them two singles. This is the first episode to feature the Fawltys' mutual sexual repression.
Alan is bamboozled when Basil interrogates him after he asks whether a chemist would still be open. Basil presumes that Alan wants to purchase a condom, and then when he states that he just wants batteries Basil presumes that they are for an adult toy. All he wants in reality is two batteries for his electric razor. The tables are soon turned on Basil, as Alan bears witness to the hotel manager in uncompromising positions with a drunken Manuel on top of Fawlty claiming that he 'loves him', and an equally inebriated Mrs. Peignoir bouncing on his back.
After Jean's parents turn up at the hotel things become more complex, and Basil presumes more hanky-panky is going on, until the situation is spelt out for him in black and white by Sybil, by which time Basil has nearly sacked Polly after getting the wrong end of the stick once more.