When Kryten was due to replaced by Hudzen-10 as the mechanoid aboard the Red Dwarf, the boys from the Dwarf decided to throw Kryten a leaving party. They made use of the usually off-limits Officer's Club and got very intoxicated, when Arnold Rimmer told them all a very embarrassing story.
When Arnold was fourteen, members of his immediate family (at least he and his mother) went on holiday with Uncle Frank and his two daughters, Sarah and Alice. Arnold was convinced that one or both of his cousins fancied him, so was very surprised when he awoke in the night to find Uncle Frank kissing him. Frank had entered the wrong room looking for Arnold's mother, with whom he was having an affair. ("The Last Day", Series III)
Many years later, software from M-Corp had taken over Red Dwarf and caused chaos. In order to perform ship-wide reset to factory settings, Rimmer had to put in his password to the reboot box - with the security question prompt of who was his first kiss with. Kryten and the Cat both remembered that it was Rimmer's Uncle Frank, much to Rimmer's embarrassment. Rimmer says to Cat that he was asleep, and that he just wants to get on. Cat asks if that it was his uncle said. ("M-Corp", Series XII)
- Arnold's brother Frank may have been named after their uncle.
- It is reasonable to assume that Uncle Frank was the brother of Arnold's father, otherwise he was having an affair with his own sister!