Girlfriend sent nudes to her collegue

My girlfriend was abroad for a semester and I found out that she sent nudes to a colleague from her internship and studies. He asked her what she was into and she wrote back that she was very submissive and liked to be choked during sex, slapped, and humiliated. Then he asked for nudes and they sent each other nude photos. He described to me what he would do to her and she said that she was “his slut and he could do whatever he wanted with her” while they masturbated.



She told me that it was a mistake and that she had never done it before and that nothing else happened. I know that the two of them pre-drunk together and also went to clubs together (with others). Unfortunately, I also saw that his cock is a lot bigger, and we've never had sex as hard as she described. Now I'm worried. Do you think she does this often? With others too? And did they actually fuck?