The best athletes in sports or NFL DE and OLB. The size, strength, and speed combination is unmatched.
Your typical NBA guard if they have the aggression would be better than the skill positions except QB, because throwing is a unique skill. Usually QBs are also baseball players.
Here in the USA a 20 year-old should not be interacting with 16-17 year old especially for a new relationship. There would more wiggle-room if say they had met while he was in HS.
But then you have people who believe any relationship with uneven power dynamics in a man's favor is problematic. But thats not this situation.