Good luck to her tbh. I hope everything goes well for her but she shouldn't be dating a man who has gotten punch in the head so much. There's been a lot of cases of violent behavior and domestic violence of men who are UFC fighters and even wrestlers.
I think its because most of them are afraid to be alone knowing most of them are in the mindset that they cant trust anyone and no one is their friend. Having a lover may put them in a state of mind that they atleast have one person they can lean on when things don't go their way.