Rose / Regina.
You feel that way because the feelings that you had for each other were very real. They didn't happen suddenly. Those feelings grew over time and were put on halt. And then were rekindled when you were reunited. Now they were put on halt again.
Everything is still so fresh in your mind that you can't help but feel like you are cheating. Just as you may not ever truly accept that he isn't coming back. You may not ever forget that feeling that you are cheating. But that doesn't mean that you are. He isn't here. And he may never come back. Or a year or two could go by before the Seal has decided he needs to be here.
You should not have to put your life on hold. Or have to wear a mask when you are around friends because you've allowed yourself to be miserable inside. The Seal manages to do that all on its own. And if we give in to its whims and allow it to tear us down we are letting it win. Don't let the Seal turn you into your own worst enemy. So, if you want to move on, move on. Push aside that feeling and let yourself find some happiness.
Take it from someone who knows all too well what you are currently feeling. There is a small part of me that with every kiss, every night of passion, every whispered I love you -- that I've given to another -- feels like I'm betraying Daniel. There is another part of me that feels that by loving Robin and his son I'm betraying the very life Greg and I were building.
But two very wise people told me that I should allow myself to be happy. And I did. So, now, I'm telling you, don't allow that feeling to fester. You are not cheating and anyone who continues to tell you otherwise will be having a meeting with one of my fireballs.