WAUKESHA, Wis. — The girl accusing Mark Chmura of rape smiled before entering a bathroom where the former Green Bay Packer was changing his clothes and flirted with him hours before she says he raped her, according to another teen's testimony.

Michael Kleber testified that his schoolmate, Chmura's 17-year-old former babysitter named Allison, also swore to him that nothing happened between her and the 31-year-old former tight end during an April 9 prom party.

"I swear on my life. I swear on my parents' life. I swear on the Holy Bible. I didn't do anything," the husky high school senior testified Allison told him when he prodded her for information about what happened inside the bathroom.

"I was scared she did something to Mark or Mark did something to her," Kleber said.

Kleber has been hailed as the star witness for the defense. Although his testimony may have shocked some, most of the trial's key players were well aware of what he planned to say on the stand. A hearing had been held before testimony began about whether a second statement Kleber made to prosecutors that differed from his initial statement would be admitted into evidence.

Although Kleber provided the most ammunition for Chmura's case Thursday, Val Buscemi, a teen who was also at the after prom party, provided important testimony about statements made to her by Allison at the party regarding Chmura's actions in the hot tub.

Chmura, who is charged with third-degree sexual assault and enticement of a minor charges, faces up to 40 years in prison if convicted.

Allison testified this week that she lied to Kleber when she told him nothing had happened in the bathroom because she wasn't really friendly with him. But according to Kleber, he and Chmura's accuser were friends — a statement that prompted an expletive from Allison's mother sitting in the courtroom. Kleber testified that he is no longer friends with Allison, whom he says since the alleged incident has called him names like "fat f***ing faggot."

The 6-foot-3-inch, 275-pound teen also detailed for the jury his claim that prosecutors bullied him into changing his statement about what happened.

He admitted on the stand that he "idolized" Chmura, who made a surprise appearance at the party as a favor to his friend, Robert Gessert, whose daughter was hosting the party.

Kleber, an All-State high school player bound for the University of Wisconsin in the fall, gave a string of "yes, sir" or "no, sir" responses.

Defense lawyer Gerald Boyle asked if he was happy when he learned of Chmura's appearance at the party.

"Oh," Kleber said, "yes, sir."

"What do you mean by the 'oh'?" Boyle asked.

"Yes, I was very excited to meet him," replied Kleber, who wants to be a professional football player.

But while many of the teens at the party were looking forward to Chmura's arrival, Allison had some choice words for their expected guest.

According to Kleber, Allison called Chmura something to the effect of "a f***ing sick guy."

"She told me that he got a 19-year-old girl pregnant, a babysitter of his," Kleber said. "I told her she was full of s***."

Kleber chalked up her bitter reaction to jealousy over the fact that the boys at the party were excited Chmura was coming to the party.

Once Chmura arrived, Kleber admits he followed around the professional player so much that even some of his friends teased him about it. But besides taking a picture with Chmura and talking with him about college and bench pressing, his shadowing of Chmura throughout the night also led him to see something no other teen at the party saw, according to Kleber.

Kleber said that about 30 seconds after he saw Chmura enter the bathroom to change his clothes, he watched Allison follow the father of two into the bathroom.

"I said, 'What are you f***ing doing?'" Kleber testified.

But the girl opened the door and gave him a grin, which he imitated for the jury, then entered the bathroom and closed the door behind her, he says.

Kleber says he ran upstairs to get her friends "to get her out of there." A group returned downstairs, including Kleber who put his ear to the door but heard nothing, he said. One of the young women, Kim — who claims to have been assaulted that night by Gessert — started banging on the door and, Allison emerged from the bathroom less than two minutes from the time she went in, he said.

Kleber also said that while Allison was playing a drinking ping pong game, he saw her flirt with Chmura, correcting him when he called her by her sister's name. Allison testified that she and two sisters had babysat for Chmura's two children. He also said that, despite her comments about him earlier in the night, she was "extremely nice" to the football player.

Kleber, 16 at the time of the party, says that although he was drinking he was not so drunk that his speech was slurred or that he was falling over. He admitted to doing some silly things that night, like licking up alcohol that spilled after a glass broke and pranking Green Bay Packer Frank Winters with Chmura, but Kleber said it was because he was "acting goofy" and "just showing off" not because he was drunk.

Even his red face, captured in a photo taken with Chmura, could be explained not by the effects of alcohol, but because he was sunburned having just returned from the Cayman Islands three days before the party, he said.

But a month after he offered investigators a witness statement, Kleber amended it, claiming that he was too drunk to remember such events clearly. On the stand, he said that he changed his story because he feared District Attorney Paul Bucher would charge him with underage drinking if he didn't.

"I don't want to go to jail for this," he recounted telling his father at the time.

Kleber said that during a meeting with prosecutors on May 11, they charged that his stories "didn't line up."

Jurors listened intently and took notes as Kleber talked about his dealings with Bucher. A couple nodded during his testimony as he spoke of his fear of being arrested and losing his scholarship. One of the older men shook his head in a negative manner when Bucher denied trying to coerce Kleber into making a false second statement.

Fearful of jeopardizing his future football career, or worse, Kleber said he gave in. "I figured if I tell them the right thing, I'm done," he said. "I don't have to worry about any of this anymore."

The boy's father retained an attorney to represent his son, and the lawyer subsequently sent a letter to both sides saying that Kleber's first statement was the most accurate and the account he would stick to on the stand.

In the afternoon session, Boyle called Buscemi, a senior at Memorial Catholic High School, who was also at the after-prom party. Unlike many of the other teens there, however, she hadn't had a single sip of alcohol that night, she said. She testified that she and Allison are not friends; they're not even particularly "friendly." But when Buscemi was leaving the bathroom at the Gessert's house, something strange happened.

"Allison kind of grabbed my arm and brought me in [to the laundry room]," she said. "She said Mark Chmura just fingered her in the hot tub."

Allison had testified that there was no contact between her and Chmura in the hot tub.

"What was going through your mind about her telling you that?" Boyle asked.

"I was shocked," Buscemi replied. "We never really talked before. We're not friends. Then she said, 'Oh, why am I telling you this?' And she left."

When Buscemi said this, a young woman juror cast a hard glare at Bucher, whose cross-examination of the witness consisted of mostly clerical questions.

Another strong witness for the defense was Pewaukee Police Chief Ed Baumann, known as "Uncle Eddie" to Kleber. In addition to being the police chief, Baumann is the defensive coordinator of the Memorial Catholic High School football team and has been Kleber's line coach for three years. He testified that before Kleber's May 11 second statement, Bucher and Baumann ran into each other in the Waukesha County Courthouse.

"Mr. Bucher said to me, 'You need to talk to your boy Kleber. He's lying,'" Baumann said. Ultimately, however, Baumann sides with Kleber, he said, and believes his first statement to be true and accurate.

Also testifying this afternoon was Thomas Thunder, an acoustics expert from Illinois, who said that the "rustling of cloths" that Allison's friend Kim said she heard outside the bathroom door was not consistent with sounds made by physical contact between two people or someone putting on clothes. He testified that in that bathroom, which had a wood floor and no carpeting, sound would resonate and echo to those standing outside listening in.

The defense is expected to call more witnesses Friday, and closing arguments could begin as early as Friday afternoon. The trial is likely to stretch into the weekend.