He decided a relationship with Wendolene wouldn't work when he found out she was allergic to cheese.

Kind of interesting seeing the series' universe develop - I remember when Close Shave came out thinking that Grand Day Out seemed like the odd duck in the series, since the idea of the characters flying to the moon just to find cheese is a bit outlandish compared to the other two. At this point you could say the same about Wrong Trousers - now the only animals are dogs in houses, rabbits in gardens and sheep in fields, it's hard to imagine another penguin lodger turning up.