Happy Valentine’s Day, you cheating pig.

No, that’s not a Hallmark card — yet. But it probably should be. As private eyes, divorce lawyers, and especially the folks selling surveillance equipment know, Valentine’s is the day suspicious spouses finally decide to get even.

Or at least, get evidence.

Then get even.

“Come Valentine’s Day, there’s a big surge in interest in tracking spouses,” the CEO of BrickHouse Security, Todd Morris, said. His Midtown-based company sells a smorgasbord of spyware, from cameras hidden in alarm clocks to handy semen detectors, to GPS tracking devices the size of a pack of smokes. Hide one of those in your spouse’s car or purse — or, as one client did, in the heel of your wife’s platform boot — and you can track his/her whereabouts minute by agonizing minute on your home computer.

Which is just what a BrickHouse client who preferred not to give her name recently did.

“It worked like a dream,” the 40-something mother said about the $950 device. (Prices start at $400.) “It’s kind of like a MapQuest map — there’s a star where you could see him. The addresses don’t come up exact, but it was close enough to prove what I wanted to prove. That’s how I established that he showed up at 7 at night and stayed till 7 a.m.”

When she confronted her husband, he had to confess. She didn’t tell him how she knew, though, because she wants to see if he goes back to his girlfriend’s house. If he does, that’s where she’s going to serve him his divorce papers.

Get those papers ready, hon. Valentine’s Day is to suspicious spouses what Thanksgiving was to Norman Rockwell: the perfect holiday.

“If somebody has somebody on the side and they don’t make contact with them in the course of Valentine’s Day, they’re in deep trouble,” the owner of a Buffalo-based surveillance equipment company, Howard Goldman, said. “So if you’re going to follow somebody, you should really follow them on Valentine’s Day, because that’s the time you’re going to hit pay dirt.”

His company, christened Goldman Computers so it would look innocuous on credit card bills, always sees interest peak at this time of year, he said, and at Christmas.

“Christmas is probably the eye-opener,” a retired New York police officer-turned-private investigator, Wilfredo Garcia, said. Here’s how:
At Christmas, the spouse receives a disappointing (read: cheap) present. Hmm.

Then, in January, the bills come in and they’re surprisingly high. The offending spouse bluffs by claiming, “Oh! I had to buy gifts for everybody,” Mr. Garcia said. But when another cheap tchotchke pops up on Valentine’s Day, the phones at Garcia & Associates start ringing.

Meantime, the do-it-yourselfers are Googling “Catch a cheat” or “Cheating spouse,” and finding all the cool new equipment that will help them sleuth for themselves.

“I sell hundreds a month,” Mr. Morris said of his company’s popular semen detectors. “There’s one that’s like a little chemistry set and there’s another one that uses an infrared light like you see on “CSI.” You can use them on a couch, a car, undergarments. …” As an added, but perhaps unnecessary, bonus, it can even detect specimens up to 30 years old.

Another device for the lovelorn is his keyboard log stroke decoder, a 1-inch cable that fits seamlessly into the cable of a computer and registers every keystroke. Log on later and up comes a document with every e-mail, Web site, and password your lawfully wedded jerk has been typing.

Yes it’s legal, if you use it on your home computer.

About 50% of all these searches bear philandering fruit, Mr. Morris estimates. And when that’s the case, it may be time to call someone like Brian Schwartz.

“We get a lot of requests for people to get divorced on Valentine’s Day,” Mr. Schwartz, a partner at the New Jersey divorce firm Ceconi & Cheifetz, said. “Some people say it’s the best present of all.”

Even better than a semen detector?

Hard to imagine.

lskenazy@yahoo.com