The sex robot craze has been widely documented, with scores of men turning to silicone women powered by computer chips.
But fans of feet are now going one step further and buying detached pairs of feet with faux-vaginas, dubbed by one firm as "vajankles".
One such website is Silicon Wives, a love doll retailer that sells "realistic silicone feet with vaginas" for $199.
"The realistic silicone feet with vaginas are perfect for the feet lovers out there that still want a traditional sex toy experience," the site's creators explain.
They went on: "This product is hand-crafted with premium medical-grade silicone to provide an ultra-realistic experience.
"The feet are highly detailed to look and feel just like real feet."
A listing for one product explains that it "can be used for vaginal sex or foot sex".
Another firm that offers more premium designs is Sinthetic.
The company provides a range of realistic female bodies – but serves up sculpted soles on the side.
Its most eye-catching product is the Vajankle, which is a detached foot with a vagina built-in.
"The Vajankle is a novelty product that was created by special request," the site's owners explain.
"It has a usable vagina in the top of the ankle."
And they come at a high price: a Vajankle can cost anywhere from $99 to $299.50.
To create a Vajankle, an in-house sculptor will work using a mix of digital scanning technology and classical sculpting techniques.
"It takes both talent and creativity to find new ways to integrate technology to redefine what can be done and continually raise the bar," the anonymous sculptor explains.
"My hands and heart go into every piece that comes out of our studio. From the sculpting development to the final delivered piece.
"There will never be a day that my hands are not directly involved with every piece that goes out the door. We will never be a manufacturing plant pumping out dolls using the lowest paid employees we can hire to make 'the product'.
"We view our work as art above all."