I disagree with the idea of Scott showing no affection. Note that when her dad the Senator sacrificed himself, it was Scott who immediately comforted her, and when he came back from the desert world, she was with him as he recovered, and he told her about his foster dad, the alcoholic priest. So there is some emotional basis for what she said.
That said, it appears that Eli has given her more overall support and been there for her in a more constant manner, but those two relatively deep times serves as a foundation for what she said in the post coital moments. That being said, I agree that it was a manipulative maneuver on her part to sleep with Scott and then get all lovey-ish with Eli.