I bet the fight will fizzle. you will both do circles saying to each other throw the first fight and no one will) then it will end.
alternatively you will fight till your both bleeding ad become good mates lol.
It would appear the advice has been covered well.
I know you said you are going to keep it clean, but be prepared if his friends (assuming they come to watch) turn on you during the fight, you will have to attack them in places you said you wouldn't go for to try to get them down in one hit, This happens more than you think, others getting involved.