A man accused of sexually assaulting a woman he was dating last year later told several people, including his roommates, that he had raped her and six other women, prosecutors say.

Isaac Wolf Yampolsky, 23, sexually assaulted a 21-year-old woman at her Chicago apartment Nov. 17, and then called his ex-girlfriend to tell her about that attack and six others, Cook County prosecutors said during Yampolsky’s bail hearing Friday at the Leighton Criminal Court Building.

Yampolsky also later told two roommates that he sexually assaulted the 21-year-old, saying it was violent and that he “should be locked up,” Assistant State’s Attorney Nancee Hofheimer said in court. He allegedly admitted to six other sexual assaults to his roommates.

Yampolsky also called “another young woman” and told her he had “relapsed” and sexually assaulted someone, Hofheimer said.

The 21-year-old woman contacted police nine days after the alleged attack, and Yampolsky turned himself in Thursday.

Prosecutors have charged Yampolsky with a felony count of aggravated sexual assault in the November incident, but Hofheimer said additional charges may be brought against Yampolsky pending an ongoing investigation by Chicago police.

Yampolsky, of Reston, Virginia, is a graduate of Northwestern University, where he was involved with many charitable pursuits, including working regularly at a soup kitchen and chairing a community outreach committee for his fraternity, his attorney Andrew Weisberg said. Yampolsky has never been arrested before.

Weisberg said Yampolsky returned to Virginia after the alleged incident, but voluntarily returned to Cook County when he learned he might face charges in the incident, even though his attorney told him that he was not charged yet and didn’t have to.

Yampolsky’s father traveled from Virginia to attended the Friday hearing but declined to comment at the advice of Weisberg, who told Judge Mary Marubio the family could afford to post bond if bail was set between $75,000 and $100,000.

Weisberg also asked Marubio to allow Yampolsky to return to Virginia, where Yampolsky sees a therapist.

Marubio denied bail for Yampolsky, ordering him held at the Cook County Jail.

Weisberg then asked Marubio if she would consider bail for Yampolsky if he agreed to stay in the county.

Marubio said no, adding, “I find 100 percent [Yampolsky] poses a real and present threat to the community.”