What's in the bag? Uh oh...

The picture that has lit up the internet. Photo / Stef Barry

Waiting for a train can be a mind-numbing activity, but not in London: there's always something going on that's worth sharing on social media.

This time that special something is the contents of a passenger's backpack.

Londoner Stef Barry photographed this young woman standing on the platform at Clapham Junction station and the photo has lit up the internet.

The unknown commuter's long pink object sticking out of her backpack has everyone who has seen it leaping to the smuttiest of conclusions.

Barry, posting the photo on the Facebook group S*** London, wrote cheekily: "Maybe she should have repacked..?"

The photo has gone viral, and has attracted some funny comments.

Members of S*** London jumped into the party. One wrote: "It's probably a feminine light saber. Give the girl a break."

Another added: "Nothing to be ashamed of except bad packing skills."

However, one member appears to have identified the object as a bottle of champagne with a pink foil lid.

Which we are sure it is.