Obi-Wan lets out a loud groan, and that's enough to have Klaus pleased as punch, smiling against Obi's throat to let him know. But then Klaus thrusts again and Obi practically shouts out a curse. Not stars, not kriff, nothing from his own world.

No, he yells out fuck, which is something that he learned from Klaus specifically. It's Klaus that does this to him, Klaus who has him shaking apart. It makes a burst of affection swell within him, along with a sharp punch of arousal.

"Perfect. You're perfect," Klaus breathes out raggedly, stroking Obi's cock a little faster. The hand around Obi's throat tightens just a little, just enough to heighten the arousal he feels, and Klaus's thrusts get a little erratic as pleasure flares out from the base of his spine. "I want to feel you come on my cock, sweetheart. Come for me."