Justin Bieber is definitely not pleased with 20-year-old Mariah Yeater and her accusation that he is the father of her baby son. Bieber recently spoke to his friend Max George -- who is a member of the British boy band the Wanted and befriended Bieber after touring together in South America -- about the baby daddy drama, and from the sound of their conversation, Bieber seems to be upset and PO'd over the whole incident.

George spoke to Mirror about his chat with Bieber, and the 23-year-old singer said, "He is really cut up by being accused of being a father. He said it’s absolute bulls---- lies and that it didn’t go down like that at all." George, who is also familiar with female fandemonium, continued, "I told him to keep his head up, we’re right behind him. He knew we’d understand because girls are around us all the time, too."

Yeater is claiming that she and Bieber engaged in a 30-second sexual romp backstage at one of his shows, and that her three-month-old son Tristyn is Bieber's child. Since the shocking accusations were made public, many people who are close to the 17-year-old performer are saying that there is no way that Yeater's story is true, including George.

"[Justin's] had the worst time of his life and handled it so well," George said. "Doing the paternity test shows how grown-up he’s being about it."

In addition to Bieber's British buddy Max George, Justin's childhood friend Ryan Butler (and Butler's parents) also said that the singer is way too smart to have unprotected sex with a total stranger. "It’s not him. Every kid in [our hometown] knows about birth control and we were brought up not to have sex randomly," Butler said of his lifelong friend. "He knows what happened to his own mother after she got pregnant with him and he knows how she struggled and he would never repeat her mistakes."

Bieber's people have confirmed that the singer will undergo a paternity test in order to negate Yeater's claims.