"I was in shock. I couldn't believe this was happening to me," said the man, 26, whose identity the Daily News is not revMaealing.
After he refused to allow McCormick to fully insert his penis into his mouth, "he told me to get out," testified the man, who said he recalled that the priest never fully took off his plaid boxer shorts.
McCormick is charged with involuntary deviate sexual intercourse, sexual assault, child endangerment, indecent exposure and related counts.
It was in December 2011 that - for the first time - the accuser told his parents and authorities that McCormick had molested him after seeing his name in the newspaper that March as one of the priests placed on administrative leave by the Archdiocese of Philadelphia over allegations of sexual abuse. McCormick was arrested in July 2012.
"I couldn't go on living if I knew this happened to me and I didn't say anything. I don't want this to happen to another little boy," the accuser said when Assistant District Attorney Kristen Kemp asked why he finally named McCormick.
During opening arguments yesterday, Kemp told the jury that McCormick, 57, was, in fact, a molester who preyed on a boy who was already living with confusion over his sexual identity and his parents' pending divorce, while defense laywer William J. Brennan said the accuser's memories were addled by addiction and too much time having past. Testimony resumes today.
Kemp told jurors that McCormick "groomed" his alleged victim for months, giving him treats, the run of the rectory and other special privileges.
The day of the attack, the accuser testified, McCormick invited him back to the rectory after Mass and gave him two cookies and Dr Pepper before luring him upstairs to the bedroom.
In the days and weeks afterward, the accuser testified, McCormick repeatedly told him that homosexuality and masturbation were sins. As a homosexual, he said, that made him feel "horrible."
"He used that position of authority first to gain access and then to maintain silence," Kemp told the jury, adding that despair about the experience drove the boy to attempt suicide at age 11 and later abuse drugs and alcohol and pingpong in and out of counseling.
Kemp warned jurors that they would see no physical evidence of an assault and would have to judge McCormick's guilt on the words of witnesses' testimonies.
Witnesses include another altar boy whose mother twice reported McCormick to church officials, and a first cousin of the alleged victim who testified yesterday that her cousin told her he'd been molested about a year after the alleged attack - but did not say by whom.
Kemp also addressed any skeptics who might think the accuser made up his abuse allegations in hopes of a payday.
"He has not filed a lawsuit. He is not in it for the money," Kemp said. "This is about ensuring that man has no access to children in the future. This is about justice."
Brennan countered by questioning whether the alleged victim's battles with drug addiction affected "his ability to recall events clearly and accurately."
Further, he argued, "This is the only individual who has made a claim of molestation. How many other altar boys did [McCormick] have access to? If that's his M.O., how did others escape?"
McCormick was among more than 25 priests suspended in March 2011 for past claims of sex abuse or inappropriate conduct with children. Ordained in 1982, he most recently was pastor of Sacred Heart Church in Swedesburg, Montgomery County.
McCormick has been free on $150,000 bail. He sat stoically, clad in his black clerical garb and white collar throughout yesterday's hearing.
On Twitter: @DanaDiFilippo