A portly Long Island perv thought he had the perfect Valentine’s Day gift for the “13-year-old girl” he was trying to hook up with — himself stuffed into a bright purple shirt that read, “My girlfriend is the coolest,” authorities say.

Creepy home-school tutor Jeffrey Weber, 59, had planned to meet the “girl” he’d met on Craigslist for a morning date that he hoped would end at her home, according to a criminal complaint.

Days earlier, on Feb. 2, Weber had sent a smiling photo of himself giving the peace sign to his would-be victim while wearing the shirt that said, “My girlfriend is the coolest, sweetest, most gorgeous woman I have ever seen. She is my best friend and my life,” officials said. The “girl” was actually an undercover cop.

In a message to her, Weber also allegedly wrote, “I had this shirt made up special for you today.”

When he showed up at a Manhattan diner for their “date” Wednesday morning, he was wearing the same purple shirt, authorities said. He was busted by waiting cops around 10 a.m. When police nabbed him, they found candles, condoms, lubricant and towels with him, the complaint states.

The pair had corresponded several times between Jan. 30 and Feb. 14 after Weber responded to a Craigslist ad posted Jan. 30 titled “Looking for an Older Guy,” authorities said.

In his explicit messages to the undercover Jan. 31, he acknowledged that she was a child and that their potential tryst was illegal, officials said.

“Since you ARE [a] virgin and you ARE a minor in terms of the laws of New York State, you KNOW that IF you and I ever did anything sexual…that you could NEVER tell anyone or I would go to jail,” he wrote to the girl, according to the complaint.

Later in the conversation, Weber wrote that he would have to say “no” if she asked to have an sexual relationship before she turned the legal age of 17, authorities said. But the conversation then soon allegedly shifted back to the topic of sex.

“Of course, we would have to make the occasion of losing your virginity very special,” he wrote, according to authorities.

The next day, Weber allegedly discussed with the “girl” how they would have to pretend he was her stepfather so he wouldn’t look like “a dirty older man with a 13 year old minor he wants to have sex with.”

Weber was charged with attempted rape, attempted criminal sex act and attempted acting in a manner injurious to a child, cops said. He faces up to life in prison if convicted.