He did indeed say something like that a few times, yes.

↓ Transcript
<Shara dreams of Gideon>
Gideon: You are nearly there, Shara. Soon you can hold me in your arms again!
Shara: Where are we?
Gideon: At my resting place. I've spent a long time here ... alone and scared ...
Shara: Scared of what?
Gideon: The WORLD. My MOTHER. You know how it is with mothers ...
---
Shara: YOU have a mother?
Gideon: Of course I have, Shara. You've met her, remember?
Shara: No I meant the ... other you.
Gideon: <sighs> Is the distinciton really that important? But yes, I guess that means I have TWO mothers now. Doesn't really make it better, does it?
---
<Shara looks to a giant statue of a byzarian woman>
Shara: And who is THAT? Don't tell me THAT's your mother.
Gideon: No, she was more of a ... sister to me. She saved me back then and brought me here. But she is long gone now ... I need YOU, Shara.
Shara: A SISTER, huh?
---
Shara: Didn't you use to say to me ... "WE SHARE BLOOD"? Doesn't that make ME a sister, too? That's kinda gross considering that we're ... well, FUCKING.
Gideon: It's all a lot more complicated actually ... but you don't need to worry about it. Our love is ABOVE all those categorizations, Shara.
Shara: You know, a lot of people say that before theay to really, REALLY nasty things.
---
Gideon: ... you make it sound like you don't want to be together with me anymore, Shara.
Shara: NO! No ... I didn't say that!
Gideon: Are you sure? Because you seem kind of ... REPULSED by me. And that makes me ... sad.
---
Gideon: Do you want me to leave you alone?
Shara: No, please DON'T! Please STAY WITH ME, Gideon!
Gideon: I thought so. Don't worry my love. I WILL NEVER LEAVE YOU.