A 32-year-old woman testified yesterday that a man who raped her returned to her apartment after he was released on bond and raped her again, swearing that "if he was going to jail for what he had done, he was going to do it right this time."

Michael A. Kay, 29, of Reston, who has been held in the Fairfax County jail on $100,000 bond since he was charged in the second rape, pleaded not guilty to both charges in Fairfax Circuit Court. His attorney argued that in both cases the woman had agreed to have sexual relations with Kay.

Choking back tears during much of her three-hour testimony, the woman described the two times--May 16 and July 7--she said Kay confronted her in her apartment.

She said she had known Kay for about nine months because his wife had baby-sat with her four sons. The woman said she let Kay into her apartment May 16 because he had agreed to work on her automobile. She said he then made sexual advances toward her and raped her.

"I laid there and I just cried," after he left, the woman said. "I went to call the police, but I hung up. I was scared. I didn't know what to say to them." She said she reported the attack to the police several hours later.

Kay was arrested and later released on a $3,000 bond.

The woman testified that he returned July 7 and was let into her apartment by her 10-year-old son who recognized Kay, but was unaware of the previous incident.

She said she was shocked that Kay had returned and sent her four sons to the three different bedrooms in the apartment to ensure that none of the rooms would be vacant in the event of a second attack.

But she testified that one of the youngsters left his room to sleep with two of the other boys, and Kay forced her into the vacant bedroom, raping her repeatedly.

"I started to scream and cry," she said, adding that the children apparently had gone to sleep and were not awakened by the noise.

Her 10- and 12-year-old sons testified that they fell asleep and were unaware of what may have happened in the next bedroom.

Kay's court-appointed attorney, Myron J. Teluk, charged that the woman "is fabricating rape charges against Kay" and that she consented to sexual relations with him on both occasions.

"She starts crying and says, 'We shouldn't be doing this,' " Teluk said. "The next thing you know he's arrested for raping her."

Arguments before the six-man, six-woman jury and Judge F. Bruce Bach are scheduled to continue today.