Nope. That’s just another battery. You don’t get to hit back. Nobody gets to hit. Not first, not second, not third.
The OP’s playful punch was wrong. The other guy’s retaliatory punch was wrong. Any further retaliation by the OP would be wrong. It’s all wrong and no one in this scenario is right.
Where does self defense fit in? Surely if someone assaults me, I have the right to defend myself from harm?
Retaliation is not defense. And self-defense is the use of necessary force to prevent imminent harm.
If the harm is over and done with, no use of force is justified.
The OP has not described any circumstance under which he would have been be protecting himself from imminent harm.
Wasn’t the face puncher supposedly defending himself?
Pretty sure this is satire, folks.
I understand your point, but it’s kidding around only within the context of those friendly environments. This isn’t one where that understanding necessarily applies.
My take on this is that your “playful” ways have been annoying him for a while. When you hit him, he was, as they say, sick of your shit. His hitting harder was his way of letting you know this.
Well, I dislike people doing anything with my abdomen, I have had enough surgery that it would be distressingly easy to split muscles at healed surgical sites and herniate me [which can potentially kill someone if it does not get proper treatment.] My husband has had 4 different procedures for repairing hernias in 2 locations [and has had several placements of mesh] and it could potentially happen to him as well. How do you know that someone has not had recent abdominal surgery and you could do serious damage even at 1/10th strength?
Do what most people do, hit the bicep, it is a reasonably innocuous location unless someone is just healing from a fracture or surgical procedure - or how about NOT hitting people to start with?
That’s just crazy talk! 
You’ve had 7+ years to plan revenge and that’s all you’ve come up with?
Take out the supposedly and sure.
You hit someone first, utterly unprovoked, now you want to cry because you got the worst of it. Judge Judy would have no patience for you.
Perhaps the OP was being obnoxious; at the very least he was acting playful with someone who he had not actually developed that relationship yet.
But he was out drinking with friends, and when people drink they tend to act that way – they will put their arm around people they barely know, they’ll tell strangers intimate details of their lives, and they may even attempt horseplay with acquaintances with fake punches to the stomach.
If you are someone who is so touchy that they react to this horseplay by punching someone in the face… you probably should avoid that sort of environment.
There was the time when I was helping my friend panel his basement. His 2½ year old son came downstairs to the basement with tears filling his eyes and his bottom lip sticking out a mile. I asked him what was wrong and in a voice filled with the kind of righteous indignation that only a 2½ year old on the verge of crying can muster, told me “Ashley hit me back!” Ashley was his 4 year old sister. At a loss, I thought MY wisest course of action was to direct the young lad to his father.
The OP is of the get drunk and surprise people you’ve been drinking with by punching them in the stomach because we’re friends school of thought.
The other guy is of the get drunk and punch someone in the face if they unexpectedly punch you in the stomach school.
Oh, and the OP is of the whine because someone hit him back school.
They ought to just agree to meet each other at the bicycle rack during recess. And to bring their lunchboxes.
Do you believe the stomach punch was an actual punch to the stomach? Or a fake punch to the stomach? Or do you not understand how the two can be different?
Someone you knew?
This short video on how The Bully From “The Karate Kid” Is Actually the Hero is kind of relevant.
It doesn’t matter what I believe. In this instance, I was not the recipient of said stomach punch. And if any contact was made, even if it was only 10%, then it was an actual punch. Look on the bright side… that punch in the face that DP got? Maybe that was dialed down to 10% also…
I, for one, am having trouble with this distinction. The stomach is the soft underbelly. I don’t see how you can punch it, without warning to tighten the muscles, and not risk actually hurting someone. If the op had said he’d lightly punched a guy in the arm, I would have more sympathy for him.
As it is, he’s lucky his victim didn’t punch him full out in the face. And since no actual damage was done to his face, we can be pretty sure that was just a “playful” punch to the face, despite what he said.
You hit him … he hit you. No matter how many fights you have been in, you do not know if he could have hit you harder had he chosen to.
You started it, he followed up with one punch. Then you both decided to stop at that point. It is done.
I also find it comical how you have asked for other’s opinion of this, and when given it try to explain why they are wrong.
If you don’t want to get hit, do not hit someone else.
If you don’t want someone’s opinion, don’t ask for it.
It does matter what you believe because I’m having a conversation with you and trying to figure out why your responses are so puzzling. So far it seems they boil down to something like 1/10 X = X. which just doesn’t seem right.