Sounds like they didn't actually fuck until she was 18 or 19. Not into hanging a guy for a thought crime, especially when they're still together. Maybe he just met his soulmate when she was at a young age and waited for her. I also think calling him her coach is a stretch. They had the same coaches and trained together at the gym. She was a prodigy and got high-level training at a younger age than most.
Maybe I'd think differently if Pat had a history of having a predilection for underage girls and exploiting and taking advantage of them. But he just seems like a solid dude to me who is very loving and loyal to her. He loves her whether she has long hair or no hair, dolled up or dressed down. I think she'd be worse off without him than with him. But you all can make up your own minds on this.