Dragon Age Origins Leliana Romance?

Does anyone know how to get this achievement. I have got her favor to 100 and talked to her about everything, given her more or less all her gifts, and still no sign of doing the deed . Am I missing something?

Maybe you got other romances, and at one point, when Leliana confronted you about them, you accidentally said “I choose the other one, not you” and forgot about it. That makes any further romance impossible.

I know I hooked up with her after being with Morrigan a few times and then Leliana said “Choose!” and I said “I love you so much” and then I started boning her.

Let’s Play Dragon Age: Origins Part 132: Flowers for Leliana