You paint a very vivid picture of who Danel is. I think that is what makes the story work. And his thoughts drifting to Marietta while he has sex for the first time with Audrey was a really nice surprise that gave the whole story some emotional stakes I really liked.
I also loved the detail of the record playing in the background and the lyrics accompanying the scene. You could have leaned into that even more for me.
I probably would have leaned into the awkwardness and inexperience of first sex a bit more. If you have him come three times in quick succession then why not give him a very quick early ejaculation? That could have played nicely into the "more exprienced woman seduces younger man"-theme you had there. I don't think that portraying sex in a non-idealized way kills the erotic charge of the scene. On the contrary, I think if you had him come early and be all flustered but Audrey reassures him saying something like: "I love how eager you are for me, Daniel. Don't worry, young lads are ready quickly again. That's why I chose you." and then she starts blowing him, then this would have fit your story perfectly and would have felt more intimate and hot for me. That would have underlined the "Did she use me...?"-questions he's asking himself nicely and would have carried his characterization as a slightly awkward boy nicely into the sex itself.
But overall, I liked the story a lot. You gave us an emotional, messy, character driven story that embraced the consensual requirement of the contest rather than fight against it. I really enjoyed that! Give me more of this short story HistBuff.