I did care about the storyline, but it just dragged on and on. I think the pacing with doing lewd stuff with Erynn actually works really well, when MC and her begin growing close (after he agrees to help her, then training camp) she's got abandonment issues and trauma due to the video. She wants more, she directly says so, but has a mental block. They slowly work through it, and she realises he's not going anywhere, the photoshoot is almost a commitment thing for her where it shows how far he's willing to go for her, but also forces them into an intimate setting and it builds naturally from there. It's slow, but it works well for the story. I think 15 could potentially be the first time, maybe 16 if she wants to wait until the Blackmail situation is resolved, but nothing that's been said points to that.
The training camp was really the catalyst for all the main girls, it's when you begin to grow really close with Layla, Lexi tells you she loves you and Erynn seems a lot closer to MC when he returns