I certainly don’t look down on it. But I have given it some though. Mainly based on my own events, and how it worked for me.
First, for me, I had no feelings for the OW I saw at all. It was simply for “fun” and ultimately understood to be a distraction.
So, I can see out it would be different if you actually did have feelings for the person.
However, you did state that you still only love your W. So the question of whether it is fair to OW? It is a fair question to ask. But that is not my focus. You can decide for yourself.
For me, my decision came, like I noted above, that it was only a distraction.
And what I found was, the distraction that is harmful is not the distraction from the negatives (thinking of W, D, OM, etc) but a distraction from the positives.
It kept me from having to actually look at me, what I really wanted, how I was going to actually move forward, learn from this, accept what is, and bring peace back into my life.
So at the end of the day, I look back at it as time wasted.
Now, your sitch may be different. You may find that it does really help you move forward. But I would keep on eye on this and answer the question honestly, for you.
BITS
Happiness is not something ready made. It comes from your own actions.