A dating website for married people seeking illicit affairs has revealed a new trend among its female users.
Since its launch in 2009, Undercoverlovers.com noted that most women on the site wanted to hook up with an older man (while male members were predictably searching for younger lovers).
However since the beginning of 2012, more than 50% of the site's female members now look for younger guys to cheat with.
Extramarital affairs website reports the rise of the 'cougars'
The website researched the profiles of all of its 663,000 members to ascertain their age when they joined and stated age preference for an affair partner.
Undercover Lovers spokesperson Emily Pope comments: 'We are surprised to note this new trend on our site."
"Middle-aged Hollywood film director Rupert Sanders and Anthea Turner's husband Grant Bovey, both of whom are currently in the news for their alleged indiscretions with 20somethings, are just the latest high profile examples of the historical norm."
Did you know these celebrities also couldn't resist the allure of their colleagues?
She continues: "'The spate of 'cougar' media stories over recent months, such as married, 32-year-old radio DJ Lucy Horobin's conquest of teenage, One Direction band member Harry Styles, may be indicative of the new trend we've identified, or inspiring our female members to seek out a younger stud."
Relationship expert and psychologist Dr Amelie Duval is not surprised by the survey results however.
"Men generally hit their sexual peak in their 20s, while with women it's much later, in their late 30s or early 40s. It's small wonder then that older married women, many of whom will have already had their children and seen them fly the nest, should seek sexual and emotional excitement with a younger lover if they're not feeling fulfilled at home."
Undercover Lovers member Mary, a married 45-year-old physiotherapist from Essex, is secretly dating Tom, a 34-year-old City trader.
She says: 'My much older husband provides me with all of the safety and security I need but none of the excitement in bed. With my young lover Tom I bring experience, wisdom and spice to the relationship whilst he brings youthful energy and sexual staying power!'
Would you know if your partner was having an affair?
The majority of UndercoverLovers.com members are in their 30s and 40s. In the years 2009-2011, 83% of the site's male members were seeking younger lovers, whilst only 36% of female members expressed a preference for a younger man.
Since the beginning of 2012, 52% of women now wish to find partners younger than themselves whilst the figure for men has remained more or less consistent at 84%.