Two Pennsylvania women have been charged with having sex with a 15-year-old boy during a pizza party where alcohol was served.

Tonia Simms, 37, and Melissa Weaver, 26, were arraigned Tuesday on multiple counts of statutory sexual assault, involuntary deviate sexual intercourse, corruption of minors and indecent assault.

According to a probable cause affidavit, the sexual encounter between Simms, Weaver and the teenage boy took place on July 8 at the older woman's apartment at the Holiday Acres housing complex in Derry Township.

Women charged: Tonia Simms (left), 37, and Melissa Weaver (right), 26, are accused of having sex with a 15-year-old boy during a pizza party where alcohol was served

The incident took place July 8 when Simms invited Weaver and the teenager over to her apartment at the Holiday Acres housing complex in Derry Township, Pennsylvania (pictured)

The document, obtained by TribLive.com, states that the 15-year-old and Melissa Weaver arrived at Simms' residence for dinner, which featured pizza and some alcoholic beverages.

After they ate and drank, Simms went upstairs to put her children to bed, while Weaver and the boy stayed downstairs.

Having tucked her kids in for the night, Simms then allegedly invited her guests to her bedroom, where according to the affidavit, the trio got undressed.

'After they were all naked, the child victim said that Melissa looked at him and said, "What, you've never had a threesome before?”' State Trooper John Zalich wrote in the affidavit.

The document states that the two women then proceeded to have sexual intercourse with the boy and with one another.

Confession: Simms (pictured left in mugshot) reportedly told police she and the teen had sex on more than one occasion. she called what happened between them a 'big mistake'

When the teen went to police about the incident, he reportedly showed a text message exchange between himself and Simms in which the two allegedly discussed his age.

When interviewed by police, Zalich wrote that both Simms and Weaver admitted to the sexual encounter with the minor.

‘Tonia said that it started out as innocent flirting and turned into a big mistake because they all had a moment of weakness,’ Zalich said in the affidavit.

Simms also revealed that she and the 15-year-old had sex on more than one occasion.

Devoted mom: Simms has two sons, including a special-needs boy who is in need of a kidney transplant

PennLive.com reported that Weaver was released Wednesday on $10,000 unsecured bail, while Simms remains jailed in Westmoreland County Prison on $20,000 cash bail. Both suspects are due back in court for plea hearings on November 16.