The 14-year old accused of fatally slashing pretty math teacher Colleen Ritzer may have been infatuated with her and snapped when she spurned his advances, according to a new report Thursday.

“One of the theories going around is that this boy had a major crush on Colleen,” a police source told Daily Mail about suspect Philip Chism.

“She was a very friendly, approachable teacher and it is possible he completely misread her affable nature and made some kind of advance towards her,” the source told the paper.

“Whether that happened on Tuesday night, or some time before is unclear. Being the professional she was, she would obviously have told him how inappropriate that was. That may have angered him enough to act as some kind of motivation for the attack.”

Chism confessed to cops that he slashed her throat with a box cutter after following her into a women’s restroom at the school, a Boston TV station reported Thursday.

Philip Chism then stuffed Ritzer’s body into a recycling bin and dumped it in the woods behind Danvers High School, Fox 25 reported, citing a source.

The dedicated math teacher, 24, had asked Chism to stay after school so she could help him prep for an upcoming test, The Boston Globe reported Thursday afternoon.

A student, Rania Rhaedaoui, said she was in Ritzer’s algebra class during last period, along with the suspect.

“She saw him drawing during class and she just said to him, ‘I didn’t know you could draw,’ ” Rhaedaoui, a 14-year-old freshman, told The Globe.

“I sit really close to him, so I could hear,” she said.

The girl said she then heard Ritzer ask Chism to stay late.

“She just said, ‘Can you stay after with me?’ He just gave a nod.”

“There was a test coming up, and she wanted to know if he had any questions on learning equations,” Rhaedaoui said.

The cold-blooded teen then went to a nearby movie theater to watch a 4:30 p.m. showing of Woody Allen’s “Blue Jasmine” after he allegedly killed the beloved teacher.

The manager from Hollywood Hits theater in Danvers — an affluent suburb about 12 miles north of Boston — told The Boston Herald that Chism “blended right in.”

The perp — a recent transplant from Tennessee who starred on the school’s JV soccer team — was busted shortly after leaving the flick.

He was being held without bail after being charged by Essex County prosecutors as an adult Wednesday. He pleaded not guilty.

The judge approved a motion by the defense for a mental evaluation.

The suspect’s mother was at the hearing but declined to speak to the media.

A schoolmate described Chism as “antisocial” and “really tired and out of it,” according to the website Wicked Local Danvers.

Friends and students, meanwhile, shared fond memories of Ritzer, an Assumption College grad who was passionate about math.

Joe Spanos, a former teacher at Andover High School, knew Ritzer for about 10 years.

“She was beautiful on the inside and out,” he told FoxNews.com. “She’s not a fighter. She probably never saw it coming.”

The Boston Red Sox also held a moment of silence for Ritzer before the opening game of the World Series.

Ritzer used Twitter to post math questions and assignments for students.

On Aug. 11, she posted, “No matter what happens in life, be good to people. Being good to people is a wonderful legacy to leave behind.”

Ritzer’s family released a statement Wednesday afternoon asking for privacy.

“At this time we are mourning the tragic death of our amazing, beautiful daughter and sister,” the statement read. “Everyone that knew and loved Colleen knew of her passion for teaching and how she mentored each and every one of her students.”