Jodi Arias, the woman who stands accused for the 2008 Arizona murder of her ex-boyfriend Travis Alexander, testified for the second week of her first-degree murder trial on Monday.

Arias, 32, shocked the courtroom with several new allegations. She testified that in January 2008 she caught Alexander masturbating to a photo of a young boy wearing underwear, and that he physically assaulted her and penetrated her vaginally for the first time as she slept in his bed the year after she was baptized in his Mormon church.

On Feb. 6, Arias shared that Alexander's 2007 Valentine's Day gift to her were pairs of boy's Spider-Man underwear. As day 15 of the trial went underway on Monday, her defense attorney asked her a series of questions that allowed her to go in-depth about his secret fetish.

Arias said on the witness stand that Alexander gave her a three-pack of boys' Spider-Man underwear and that when she tried to put them on, they didn't fit so she made alterations to them so she could wear them for him. She said once she did, they had anal sex while she wore the underwear.

Almost a year later, Arias testified and described an incident that deeply disturbed her- she walked into Alexander's bedroom and found him holding a picture of a little boy wearing a pair of underwear. She admitted she didn't end the relationship with him right away, she instead decided to try to help him change his secret fetish.

Arias said in May of 2007 she slept in the same bed as Alexander at his home and she woke to find him having sex with her. She felt a tremendous amount of guilt about the incident and prayed with Alexander because he broke the Mormons' rule about chastity.

"Did you want him to penetrate your vagina with his penis while you were sleeping?" Arias' defense attorney asked her.

 "It was nothing I had thought about," replied Arias. "I wanted to comport with the law of chastity because I believed that our relationship would be blessed if we did that." 

Arias testified that when she brought literature to Alexander about professional help he should seek about his attraction to children, he physically assaulted her. Alexander, she said, kicked her in the ribs, threw her on the floor and when she blocked one of his kicks, her finger swelled up. The alleged murderer proceeded to hold her hand up to show the damage to her finger- her finger is permanently bent from the incident. She said she did not call the police of seek medical help because she didn't have medical insurance at the time.

Several months later, in October 2007, they had an argument because she went on a date with another man, John Dixon. Alexander shoved her on the ground of his bedroom floor, she revealed, and after the assault she considered suicide. She asked a friend for a gun to kill herself.

"Can I borrow your gun? I'd like to kill myself," said Arias.

After she revealed her plans to Alexander, she said he was really nice to her, and she went to his house where they had anal sex.

Arias' attorney had her discuss even more scenarios where she felt disrespected and "used," in order to portray Alexander as obsessed with sex and secrecy all while pretending to be a devout Mormom who had no interest in having a real relationship with Arias. Since they met in September 2006 until his death in June 2008, Alexander and Arias exchanged and took nude photos of themselves, had oral and anal sex, and eventually intercourse.

Arias stands accused of murdering Alexander, whose body was discovered in his Mesa, Ariz., home on June 4, 2008. When police found the victim, they saw that he had been shot in the face, stabbed 27 times and his throat was slit from ear to ear. If Arias is convicted of the murder she will likely face the death penalty, becoming the fourth woman in Arizona's history to die by lethal injection.

Watch the free live stream of day 16 of Arias' murder trial in the video below beginning at 12:30 p.m. EST.