Updated

BELLEFONTE, Pennsylvania (Reuters) - A sobbing 18-year-old witness in the Jerry Sandusky child sexual abuse trial testified on Tuesday that the former Penn State University assistant football coach befriended him as a boy, took him to his house and began to sexually abuse him.

The witness, testifying on the second day of the closely watched trial, said he met Sandusky when he was about 10 or 11 years old through the Second Mile charity that Sandusky founded. He described being sexually abused by Sandusky, including oral sex, adding, "I didn't want it to happen."

Sandusky is accused of using Second Mile, which he opened in 1977, to prey on needy young boys. Sandusky, 68, faces 52 counts of abusing 10 boys over a 15-year period.

The next witness to take the stand was former Penn State graduate assistant coach Mike McQueary, who is expected to offer crucial testimony. McQueary has told prosecutors he saw Sandusky sexually assaulting yet another boy, known as Victim 2, in February 2001 in a locker room. Victim 2 has not been found by authorities.

The 18-year-old witness, identified in court documents as Victim 1, testified in Centre County Court that he began spending time at Sandusky's home in State College, home to Pennsylvania State University, after attending charity events for three years.

Sandusky gradually grew more intimate with him until he would kiss him on the lips and blow on his bare stomach when the boy was ready to go to sleep in Sandusky's basement, the witness testified.

Then one day, "After cracking my back and rubbing his hands down the back of my shorts and blowing on the stomach, he, he put his mouth on my privates," the man said, holding back sobs as a silent courtroom listened.

"I didn't know what to do. With all the thoughts running through my head I kind of blacked out, I didn't want it to happen," the witness added.

The witness began to cry and said Sandusky later had forced him to put his mouth on the coach's genitals.

'IT'S YOUR TURN'

"He said something along the lines of, 'It's your turn,'" the witness said, his head bowed.

Sandusky, the former defensive coordinator for the Penn State football team, sat hunched forward at the defense table, his back to the courtroom. If convicted on all counts, he faces a sentence of more than 500 years in prison.

The charges put a spotlight on child sexual abuse in the United States and prompted the firing of revered coach Joe Paterno and university President Graham Spanier in November. Paterno died of lung cancer in January.

Prosecutors allege Sandusky had physical contact with the boys he is accused of abusing, known in court documents as Victims 1 to 10, that ranged from tickling and a "soap battle" in Penn State showers to oral and anal sex.

The 18-year-old witness testified that Sandusky had performed oral sex on him several times and he had done it to Sandusky at least once.

Under cross-examination by defense attorney Joe Amendola, he was asked about discrepancies in his testimony. He had first told investigators in June 2009 that Sandusky performed oral sex on him more than 20 times, but five months later told a grand jury it was about 12 times.

The witness said he had been afraid the first time he talked to investigators and had resolved to tell the truth to the grand jury. He also denied that he and his mother had talked about getting rich from the Sandusky scandal.

The young man's account came after a 28-year-old man, another one of the eight alleged victims of Sandusky due to be prosecution witnesses, told jurors on Monday he had kept silent about the scores of times he was sexually abused by Sandusky because he was ashamed.

But he said he decided to speak out when he realized that other boys, now men, had been abused as well. "If I had said something back then they wouldn't have had this happen to them," said the witness, who met Sandusky at about age 13 in 1996 or 1997 and testified he was abused sexually for three or four years.

Reuters' policy is not to identify victims of sexual crimes.

(Additional reporting by Matt Morgan in Bellefonte; Editing by Tom Brown and Will Dunham)