When can punching be legal?
<p>My neighbor kissed my wife. I was pissed and wanted to punch him in his face. But I was able to suppress my anger.</p>

<p>If I did punch him, would that be okay? I saw people punch one another over this in movies. Kissing my wife is adultery right?</p>

<blockquote>
  <p>If I did punch him , would that be okay?</p>
</blockquote>

<p>No, that would be Assault and Battery. If you did him serious injury you could face a charge of Grievous Bodily Harm. If you killed him, that would be murder.</p>

<p>If you are in the UK, Canada or Australia and you were charged with murder you could claim <a href="https://en.wikipedia.org/wiki/Provocation_(legal)">provocation</a> in an attempt to have the charge reduced to Voluntary Manslaughter. If you were in the US you could attempt to argue "extreme emotional or mental distress" if you are in a state that has adopted the Model Penal Code for any of the charges; if successful your sentence would be reduced.</p>

<blockquote>
  <p>I saw people punch one another over this in movies.</p>
</blockquote>

<p>And I saw aliens invading the Earth in the movies - what happens in the movies if not necessarily true.</p>

<blockquote>
  <p>Kissing my wife is adultery right?</p>
</blockquote>

<p>No, extramarital sex is adultery. Notwithstanding, adultery is not illegal in common-law countries.</p>

<blockquote>
  <p>I'm pissed and don't know what to do?</p>
</blockquote>

<p>I sympathise with you but this is not a legal question. Whatever is going on between you, your wife and your neighbour is a social situation; not a legal one.</p>

<p>The answer to your question depends:</p>

<ol>
<li>upon your jurisdiction; and</li>
<li>when the punching took place.</li>
</ol>

<p>In most jurisdictions you could use force to prevent a battery upon your wife (i.e., kissing). No jurisdiction I aware of allows you put take retribution by punching afterwards. </p>

common-law battery