It all happened way too fast for Luke.

First, he was kidnapped and dragged into some kind of.. facility? He didn't know,and no one would tell him. But, they did tell him he was gonna 'save the world', though he was kind of skeptical about it, after all, save the world from what exactly?

Then, just after he was done talking to Ms. Sigsby and walked through the corridors, he started inspecting the posters that were on the walls and analyse how many cameras the place has. Pretty smart.

Then, he met yet again Kalisha and you (btw, the kiss scene didn't happen yet and he met you at the same time when Kalisha appeared), you just came in a week ago, so you were as new as Luke, not much, since you already know what kind of torture this place is..

Then, Kalisha suddenly asked the question: "Have you ever had Varicella?" You knew what this was, she did that and kissed the person to know what other people are thinking, she tried it with you, but couldn't do it since you reacted quickly.

So, before Kalisha could pull Luke towards her and kiss him, you did it instead.

Yes, you kissed Luke. It was quick, but surprisingly Luke didn't pull away, sure, he was shocked, but not disgusted.

Kalisha pouted, noticing how you prevented her from reading Luke's mind through the kiss, but she was half-amused. She didn't think of the possibility of you kissing Luke instead.

You stepped back, trying not to appear just slightly flustered as you quickly explained why you did that to Luke.

Luke was simply frozen, processing your words like a thousand times over an over but still thinking about the kiss.