They do say no one knows what goes on behind closed doors – but is your neighbor giving out secret clues that they’re a swinger?

Yesterday we told how sales of garden pampas grass have plummeted because it’s believed to be a secret signal that swingers live in the home it belongs to.

But it turns out that the exotic plant isn’t the only giveaway that the house’s residents are into liberal sexual practices.

While The Sun Online cannot verify any of these claims, here are some of the tell-tale signs that you could be living next door to a swinger.

According to Cooper Beckett, host of the Life on the Swingset podcast, many swingers wear a black ring.

He told The Stranger: “Wear your black ring on your right hand if you are out and open to meet other swingers.

“If someone wearing a black ring on their right hand approaches you, start a conversation with them, ‘I see you’re wearing a black ring on your right hand. Maybe we are in the same club’.”

Other secret swinger symbols include a woman wearing an anklet, toe rings, thumb rings and switching your wedding ring to the right hand, according to alternative lifestyles website Bigger Love.

They also cite white landscaping rocks and pink or purple decorations in the front garden as a signal of swinger activity.

Bizarrely, the website identifies pineapples as another swinger signal – in the form of a door knocker.

They may look sweet and innocent, but it turns out garden gnomes are a likely indicator that the resident is into swinging.

An estate agent in the US found this out the hard way, when their client was warned off buying in a “huge swinger community.”

The claim is also backed up by a Reddit thread, which also suggests that pink flamingos on the lawn is a tell-tale sign, though the user who uploaded the post was skeptical.

According to the website Swinger Code, people who are up for swapping sexual partners often wear a wristband brandishing a special “sign.”

The subtle symbol was created to help swingers recognize each other and help them to find potential partners.

According to the website, the sign is “unobtrusive and respects the privacy of the ones who wear it.”

The symbol, which consists of the international male and female signs arranged horizontally with their circles intersecting, with three plus or minus signs on both sides, differs slightly depending on what the swinger is into.

The three plus signs on both sides mean they are “looking for partners as a pair” while the minus signs mean they would also join without their partner.

Having a hot tub in the garden is also famed for being a common swinger trait.

But according to Ross Phillipson, sales director at Hot Tubs Superstore in Blackpool, this is now a myth.

He explained: “The biggest misconception is that hot tubs are the preserve of swingers, indulgent Premiership footballers or flashy types who live in Essex. In fact, they are bought by anyone and everyone.”

Another sign is that your neighbor will never open their garage door until they’re in the car with the doors closed, according to a Reddit thread.