Lily Allen was forced to relieve herself on a motorway.

The 'Air Balloon' singer - who has two children, Ethel, two, and 14-month-old Marnie, with her husband Sam Cooper - had to pull her car over by the side of a road as she was desperate to pee, and she was so impressed with her public urination, she even shared a picture with her twitter and Instagram followers.

She tweeted: ''P***ing on the hard shoulder #gettingolder (sic)''

And then added: ''6m p**s (sic)''

While many of her followers saw the funny side of the updates, others were not impressed, with one writing ''grow up'', another adding ''grim'' and one user sarcastically commenting ''classy''.

Lily, 28, isn't afraid to share intimate details in public, and earlier this week she spoke of her teenage confusion on how to groom her pubic hair.

She said: ''Can we just talk about pubic hair? Being a teenager I was endlessly confused from one boyfriend to the next. They wanted completely different things [down there]. One said no, another wanted her it jazzy. They probably didn't know what they liked really.''