DM doesn't love Santu....yet.
However, I second everyone's comment above me whose been saying that he's grown to respect her, and care for her.
We have to understand that there are two brick walls in the way of DM and Santu... first, DM loves his first wife, Subhadra, more than he's ever loved another. He still believes she is in his life, and will always continue to be, in one way or the other. It's going to be really hard for him to get over her, and give her place over to another, especially to someone who is not much like her. Second, the age gap/ level of maturity. I admit, for an eighteen- year old, Santu is VERY mature for her age, and even overrides DM in some cases. But physically, and to DM, she's only a chokri. Something big will have to happen where he stops seeing her in that light and in the light of a wife. Right now, he sees her as his caretaker, and is getting used to her, opening up to her....but he will only love her once he accepts her as his wife, and he will only accept him as his wife once he loves her.
I think the next few episodes will constitute of DM figuring out that he reallly cares about santo while he's in antwerp...i'm still confused about the divorce. He MIGHT give it to her and realize he can't live without her, or he may make that realization beforehand...