I agree but let me offer a different interpretation. If Rumple is going after Robin to kill him in FTL of the past (as evidenced by the synopsis) and does succeed in killing Robin, one of the Merry Men would want revenge and would have it out for Rumple. So, you’re a Merry Man and you see Rumple’s true love all alone. Because of what happened to you in FTL you’re character has changed (like the rest of the cast) and you take this opportunity to strike. Rumple took your leader and friend and overall good guy (Robin), so you try to seduce his love. It’s within at least the realm of possibility.
This is my theory as well….God I hope Gold beats the crap out of him. 😆