Many people I talk to experience their Twin Flame being with somebody else, whether they're married, dating someone, or have kids with someone. The only reason why we experience this illusion is that our Twin Flame is bringing up something within us to heal. They're not doing it to hurt you; they're not doing it because they don't love you; they're not doing it because they don't know that you're their twin flame. They're doing it because it's their job to bring up all the places within you that are choosing separation from your good.
The first way to heal this third-party situation is to get very clear on how this makes you feel. Say you have a feeling coming up, and it brings back something that happened in your previous relationships. That's the same feeling that comes up when you see them with somebody else. Look into that using the Mirror Exercise! Feeling your feelings is the KEY to any upsets you are experiencing in your Union and reality. If you don't know what the Mirror Exercise is you can find the explanation here in this Youtube Video created by Twin Flames Universe : https://www.youtube.com/watch?v=FhSjFx04qgk
Another common reason why I see Twin Flames with somebody else is that you have a belief that your Love is outside of yourself, or you're trying to get love from your Twin Flame, making them your source of love. This energy is repulsive to your Twin Flame and could cause them to run to be with someone else. They are just mirroring your exact belief/ choice that your Love is outside of you. The way to heal this is to shift your focus from making your Twin Flame your source, to God as your source. You have to love yourself first; you have to be happy by yourself first. Your Twin Flame is not going to come on a white horse and save you. They're not going to make you feel better about yourself. You have to do that for yourself. You have to be your own savior.
Your Twin Flame being with someone else is not going to last forever. This person they're with is not you, YOU are their Twin Flame. Keep claiming that in your heart. Remind yourself of the truth because that is the truth.
Another reason why they could be with somebody else and having third-party energy is that YOU have third-party energy. You're still looking for love outside of yourself somewhere. Maybe your third-party energy is your parents, your children, or someone you were previously with. You could be leaking your energy in the form of codependency, not standing up for yourself, or not putting yourself first. Wherever there is an energy leak, where the energy is not balanced, you're seeing a person as your source, or they're seeing you as their source. Just choose to put yourself first here take care of you first and your Twin Flame will naturally start making that same choice as you.
In conclusion, it's essential to remember that Twin Flame and Third-Party relationships can be complex and challenging to navigate. However, with the right mindset and going all in with The Teachings of Unionism and Twin Flames Universe, you can overcome these obstacles and come into Harmonious Union with your Twin Flame. Nothing you desire is impossible and no other person can come between your Union. Don't give any power to that illusion and it will vanish. Thanks so much for reading and remember, you are worthy of your Twin Flame Harmonious Union!