WATCH: At The Races reporter throws serious shade with vintage 'your mother' joke on live TV

Derek Thompson just couldn't resist...

Derek Thompson

Image: Sky Sports 

This is one of the finest/most awkward/totally inexplicable pieces of post race interviewing we've ever seen.

Josephine Gordon gave At The Races the courtesy to stop and chat before heading to her dressing room after a race last night and Derek Thompson went through what must be his usual routine. 

'How did you feel the race went?' and 'what were the strong aspects of the performance?' are the usual ports of call to gauge the mood of a jockey after a race.

But Thompson wasn't finished there.

The reporter managed to sneak in one final question, asking whether or not her mother at home in Devon would be watching her race this evening.

"She'd be in bed," says Josephine.

Up to this point you think that should be it, interview over and for all intents and purposes, that's a wrap. 

Not for Derek Thompson, who promptly replied: "If I know your mum, she certainly won't."