A 23-year-old Canberra man has been found not guilty of raping a fellow student at the Australian National University in 2011.

An ACT Supreme Court jury took less than an hour to reach its verdicts on three charges of sexual assault.

The woman told the court she was raped by Lewis Todd Meegan in his room, after the pair had been on a pub crawl with other students.

She gave a tearful account of the incident, saying she repeatedly told him no.

But later in the trial she admitted suggesting a casual sexual arrangement and that she had consensual sex with Mr Meegan for months afterwards.

The court saw Facebook and text messages between the pair where they referred to sex as an "intensive debate".

The woman told the court the relationship ended when she met someone else.

Mr Meegan rejected any suggestion he had sexually assaulted the woman.

'She seemed like a lovely person'

His lawyer James Lawton asked directly if there was any sign she was not happy about the encounter.

"Was there any time that she indicated she was not consenting?" he said.

"No," Mr Meegan replied.

The woman also told the court after the encounter she told him she wanted nothing more to do with him, and ordered him not to tell anyone.

Mr Meegan said that never happened.

Mr Meegan said he had also asked her about a relationship.

"She seemed like a lovely person and I enjoyed spending time with her," he said.

But he told the court that when the woman said she would prefer a casual sexual relationship, he accepted that.

Mr Meegan said the pair would meet to watch movies and drink tea, which often ended in sex in his room.

He said the woman ended their relationship when she met someone else.