A young, shy riolu gains the duo's attention in the gym and while he's a bit reluctant at first he agrees to an invitation from the big beasts...
Kinks wanted: Wrestling, sex(you decide what kind), musk, muscle worship, wrestling, daddy kink... did i mention wrestling?
You remember your pic from winglesseddie? Try building their match around something like that...
Bearhug wanted, both 1v1 and both on riolu.
How about letting them cuddle up in bed in the end? 2 big dad's and their little boy/jobber/pet?