SOURCE

var inter = document.querySelector('.inter'),
    outer = document.querySelector('.outer');

inter.addEventListener('click', function(e) {
  console.log('in');
}, {once: true});

outer.addEventListener('click', function(e) {
  console.log('out');
}, {once: true});

<div class="outer">
  <div class="inter"></div>
</div>

.inter {
  width: 100px;
  height: 100px;
  background: #000;
  margin: 0 auto;
}
.outer {
  width: 200px;
  height: 200px;
  background: #333;
}