The mother of an 8-year-old boy who was allegedly sexually abused by a woman who considered him her boyfriend said she knew something was wrong when the boy began to act out at school and even threw a chair at another student.

"He tried to jump out the window at school," the woman said Monday. "He was acting out last year — all kind of stuff."

She said he would cry if he wasn't allowed to go to a neighbor's house, where he helped a 7-year-old girl with her homework and played games.

Then the woman's older son found a letter in his brother's room that shocked the family and authorities. The letter led to charges that the girl's 29-year-old mother, Tammy Imre (search), had engaged in sexual relations with the boy.

Imre, a divorced, part-time receptionist, has been charged with multiple offenses, including sexual assault and risk of injury to a minor. A judge set bond at $250,000 Monday.

According to the arrest affidavit, Imre told investigators she considered the relationship "like a fantasy and she was the girlfriend and he was the boyfriend and that someday they could end up together in a relationship."

When confronted, police said Imre acknowledged having sexual acts with the third grader. In the affidavit, Imre describes kissing and fondling the boy and being in bed together naked.

Authorities said it is unclear when the alleged abuse began.

The boy's mother said her son visited Imre's house nearly every day for at least a year. Imre would take her daughter and the boy to the neighborhood playground and out to eat at a fast food restaurant. She even took the boy to a mall and would buy him toys and other gifts, according to the boy's mother.

"We were mothers of two children who go to school together," the boy's mother said. "She seemed like a good friend."

An investigation began in September after the boy's mother discovered the letter, in which Imre tells him that she doesn't "want anyone but you. Now tomorrow it's supposed to rain, you can come over we can (you know what). Love ya! I want you!"

The boy at first denied kissing or touching Imre, but later admitted having intercourse with her, according to the affidavit. He also told investigators Imre gave him a key to her apartment.

Evelyn Imre, the suspect's mother, said her daughter had "a little mental problem" but she declined to disclose details.

If convicted, Imre could serve more than 20 years in prison.

"I just feel justice needs to be served and it's going to be," the boy's mother said. "She ruined my child."