Grealish, 27, and Mendy, 28, had been at the China White nightclub in Manchester city centre before going back to Mendy’s Cheshire mansion, The Spinney, in Prestbury, when the women were attacked, Chester Crown Court heard.
One, 23, said she was raped by Mendy’s co-accused, Louis Saha Matturie, 41, in a car when they went to get more drink.
She told a second girl, 17, who claims Mendy raped her, she had also had sex with Grealish, the court was told.
Both Mendy and Matturie deny multiple sex offences against a string of young women.
On Friday, jurors were played a police interview from the young woman accusing Mendy and Matturie of rape.
Seventeen at the time, she says Mendy raped her twice at his home during the gathering, where Mendy’s friends and Grealish’s friends, from Birmingham, were also present.
She told police Matturie asked her to the nightclub in the early hours of last August 23.
She arrived at around 3.30am and was outside the club shortly before Mendy and Matturie left.
She said: “They were with Jack Grealish. There were a few girls around him but they were taking pictures and video with his friends.
“The club did not like that. They wanted the pics to be deleted.
“There was a bit of a talking to. It took a while for them to come out.”
The teenager got a taxi with three other girls and one of Matturie’s friends, and passed around drink on the way to Mendy’s house, where the girls had their mobile phones taken away before going inside, the court was told.
She said: “There were already two girls on the couch. They were sat next to Jack. He was already on the couch.”
Matturie then led the 23-year-old woman away “hand in hand” to get more alcohol because, the witness told police, “Jack had been demanding vodka”.
Matturie then allegedly raped the 23-year-old in the car they used to go to a shop at a local petrol station before returning to the house.
The 17-year-old told police: “I asked her what happened. I took her to the toilet. She’s absolutely distraught, in hysterics.
“She just told me she had fallen asleep in the car and woke up with the feeling of him pushing inside her.”
The teenager told police she felt “uncomfortable” and did not know what to do but had no phone to call for help.
Later, in a lounge area, she said Mendy began “checking her out” before leading her to an office with a secure lock.
Inside the office, Mendy allegedly raped the teenager twice.
She told police: “We did not talk about sex beforehand and afterwards we did not talk about it.
“There was nothing of the sort to suggest we were going to engage in sex. During sex he was telling me, ‘This is not the body of a 17-year-old. This is not the arse of a 17-year-old. I want you every day.”
Afterwards, the 17-year-old went to find the 23-year-old woman and found her in a lounge.
She told police: “She told me she had sex with Jack.
“I don’t know whether that was consensual or non-consensual. I don’t know what that was. But she was talking about it.
“I know that this was after I had been with Ben, because after she had gone to bed with Ben as well.
“She had been taken up to a room with Ben. This was a bedroom.”
The teenager said she was raped in a cinema room by Matturie after being raped by Mendy.
She said she saw Grealish “passed out” in the house.
She said she was raped again by Matturie at a Manchester flat on the same day.
Prosecutors claim Mendy is a “predator” who “turned the pursuit of women for sex into a game”.
Matturie, his friend and “fixer”, allegedly had the job of finding young women for sex.
Mendy denies seven counts of rape, one count of attempted rape and one count of sexual assault against six young women.
Matturie of Eccles, Salford, denies six counts of rape and three counts of sexual assault relating to seven young women.
Both men say if any sex did take place with women or girls it was consensual.
The trial continues.