Ooh, those all sound really good to me! Kris would feel bad about hurting Siobhan, but he probably would've gotten all freaked out, thinking that their families would start talking marriage which he was very not ready for. And he probably would have rationalized that he was doing what was best for her. Since they were teens at the time, he'd pretty much pretend it didn't happen/flirt with Siobhan as normal, glossing over any awkwardness.