The 46-year-old actor said the two characters share a deep personal bond but the "GOT" fans should know the elder Lannister son is committed to his fraternal twin, Cersei, reported ContactMusic.
"I think they have this real affection for each other, and respect, and most importantly, they have real trust. (But) do they have romantic feelings for each other? I don't think he's really capable of (that).
"Unless he's able to completely leave Cersei, I don't (think) that's gonna happen. I think he's a very monogamous man. He's faithful," Nikolaj explained whilst talking on Variety's podcast, "Remote Controlled".