Yes of course! Look, you either choose your Twin Flame or you don’t but you can’t have it both ways.
Same applies to normal relationships; You either commit or not and there is a difference in whatever choice that you make.
Imagine if you are a Twin Flame and your partner is sleeping with others, would you rush to be with them? — No! — You would assume that they moved on.
You will have doubts as to whether they are your divine partner or not. You will also trust them less if they don’t have the patience to wait for you.
Secondly, I believe that sleeping with others while you are going through a Twin Flame connection bogs down your energy in the connection.
Imagine waking up in someone else’s bed when you are tormented by your Twin Flame’s energy? It will complicate the situation for you.
From my past experiences, having sex with others entangles your auras with others. Every time you have sex with someone, you take some kind of energy from them.
The Twin Flame connection is about clearing energy and karma — I believe that sleeping with others only taints your energy which slows down your healing.
I hope that my experience helps you.