Lee Mack had to "clean the end" of Red Rum's member.
The 'Not Going Out' star has had his fair share of bizarre jobs and even spent time as a stable boy for trainer Ginger McCain, which meant getting very hands-on with the legendary racehorse's equipment.
Appearing on Sky One's 'A League of Their Own' this week, he says: "One of the jobs I had to do - and this is genuinely true - you have to wipe a horse's bottom when you work in a stables. But not just the bottom!
"You have to get the wet sponge and - you know how a horse's penis retracts into its body? You've got to get the sponge in there and clean the end of the penis."
Show regular Freddie Flintoff hosts this week, and Lee, 51, mocked him for asking whether Red Rum had "won the Grand National" by that point.
The comedian quipped: "How old do you think I am?! Yes he'd won the Grand National! He'd been retired for about seven years then."
The horse won the notoriously difficult race in 1973, 1974 and 1977 - an unmatched treble - while also finishing second in the two intervening years.
He retired the year after his final triumph, when the comic was 10 years old.
Panellist Jamie Redknapp also weighed in on Lee's experience, and quizzed the comedian about the thoroughbred's retirement.
The actor joked: "What do you mean, 'Was he looked after?' I used to clean the end of his k**b! Course he was looked after!"
'A League of Their Own' is on Sky One and NOW TV on Thursdays at 9pm.
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