Right click to enable "open in new tab/window"

document.body.addEventListener('click', evt => {
  const link = evt.target.closest('a.use-loader');
  if (!link) return;
  evt.preventDefault();
  document.body.innerHTML = '<h1 style="color:red">LOADING</h1>';
  window.location.href = link.href;
});

<a href="https://example.com" class="use-loader">
  This loads <em>really slow</em>, and it's my responsibility to fix that.
</a>
<br>
<a href="https://example.org" class="use-loader">This one, too.</a>

$('body').on('click', 'a.use-loader', function () {
  document.body.innerHTML = '<h1 style="color:red">LOADING</h1>';
  window.location.href = $(this).attr('href');
  return false;
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<a href="https://example.com" class="use-loader">
  This loads <em>really slow</em>, and it's my responsibility to fix that.
</a>
<br>
<a href="https://example.org" class="use-loader">This one, too.</a>