SAN ANTONIO - Floral shops are not the only businesses with their phone ringing off the hook for Valentine’s Day. Local private investigators said they are seeing a spike, too.

Relationship experts said that’s because Feb. 13 is considered “Mistress Day.”

While KENS 5 is not condoning this behavior, we are reporting on a trend and statistics that support the theory.

When you think of Valentine’s Day, flowers, candy and candlelight dinners may come to mind.

Hidden camera stores also reportedly see a surge in sales before Valentine's Day.

“People are worrying about what their spouse is doing on Valentine’s Day,” said a private investigator who did not want his name given in this report. He was, however, ok with showing his face on camera.

For the past eight years, he said his local company, Aces Private Investigations, has been the bearer of bad news to an average of 40 clients a month.

"Equally, 50/50 men and women are our clients,” he added. He said business always picks up the second week in February.

"There is no season for it,” he said. “Of course people are going to get more suspicious around Valentine’s Day."

According to research done by Ashley Madison, a website created for "discreet encounters," cheating husbands are likely to spend more than twice the amount of money on their mistresses compared to gifts for their wives. That's to alleviate the guilt.

Catching a cheater can cost a lot, too.

“We help people find what they are looking for,” said the local P.I.

“We use [devices] for a lot of surveillance. [For example, there] is a game camera you can post on any tree. You have GoPros and night vision, smoke detectors with a camera inside and an earpiece, but it’s actually a camera that connects to a cell phone,” he described.

For $49.99, there's even a cheating spouse kit that will ship to your home.

While the business said it is well equipped to follow cheaters, there are red flags you can watch for.

"Hiding their phone, telling small lies and not responding to texts [for example],” he said.

For more information on these services, click here.