Basically, a good friend of mine has been with her DP for 9 months and is very happy with him. They met through a mutual friend.
Her DP seems nice and they are now talking about moving in together. He always tells her how attracted he was to her since the first moment he saw her.
Anyway, I went out with a group of people from my primary school - my friend does not socialize with them. There was a woman who looked just like her, the same hair colour and style, figure, they even move in the same way and could easily pass as sisters. I mentioned it to one of the people I was with, who vaguely knows her. It turns out she is my friend's DP's Ex. They were together for 6 years.
I am now wondering whether to say anything to my friend, I think she would be deeply hurt to know that the instant attraction was probably due to her looking like his ex. And I don't want her to know that I knew and didn't say anything. I am struggling to imagine what I would feel like if I was her and found out. I might be massively overthinking it, I have known for over a month and it is really bugging me.