Ansel Elgort denied an allegation he sexually assaulted a woman he dated in an Instagram post on Saturday, days after the graphic allegation was shared on Twitter and quickly went viral.

A woman on Twitter, identified only as “Gabby,” posted a detailed account of her relationship with Elgort, who she claimed took her virginity in a painful experience she described as a sexual assault. The details are graphic but were shared by Page Six:

Gabby, who appears to have deleted her Twitter account after posting her message, had written that “when [the sexual encounter] happened, instead of asking me if I wanted to stop having sex knowing it was my first time and I was sobbing in pain and I didn’t want to do it, the only words that came out of his mouth were ‘we need to break you in.’

“I WASN’T there in that moment mentally,” she wrote.

The woman said the two met on social media and offered other details about their relationship. Elgort did not comment on the post until Saturday, when he confirmed that the two had a relationship but said it was “legal and entirely consensual.”

Elgort said he was “disgusted and deeply ashamed of the way I acted” and apologized for how he ended the relationship, but he denied the sexual assault claim and said “her description of events is simply not what happened.”