Kate Beckinsale used a photo of Madonna's backside to prank her daughter

She shared their text exchange on social media, as she first wrote: "Do you think it's too much that I posted this? The thing is my a** looks good."

Lily replied: "I'm a little confused I must say. I do think it's a little much but it's also very arty".

However, Kate quickly revealed the photo was actually Madonna's viral snap, and she teased her daughter for not realising.

She added: "Like I'd ever... I can't believe you can't recognise your own mothers anus from under the bed (sic)".

Lily described the exchange as a "rollercoaster" while Kate admitted she was "snorting" and "crying" laughing.

Lily replied: "I couldn't even sign onto Instagram and check I was so confused. I'm so relieved.

"I legit sat down to deal w that. My coworker came up and asked if I was on break (sic)"

She insisted she wouldn't have even been "embarrassed" for herself if her famous mum had actually posted her own snape like that, but she "would be concerned".

Kate added: "As if I'd take and post that you maniac".

Lily replied: "No I know that's why it was so jarring".

And the 'Pearl Harbour' actress quipped: "Well quite also what am I doing under the bed and when did I get that rug".

Meanwhile, Kate - a notorious prankster - admitted her fear of payback means she won't drop off in front of other people.

She previously said: "I've thought about this - I would never fall asleep in front of other people. That's very risky.

"You could wake up with no eyebrows or a moustache or a sanitary towel stuck to your head.

"But when it's very early mornings... Sometimes when you're working at 3 in the morning, I don't care so much about eating but I really need to sleep."