I think what he meant by "I have someone" was that he has his mother to prioritise at the moment and don't have time to keep a girlfriend happy. Hope this is what he meant. Other way is also fine.....Anything that makes it more interesting and sweet.
Kyon has become more courageous after regaining his memories. He seemed to be the type who needs to be protected but now it seems that he can protect too.
Since, they both truly love each other without any adulteration, even Kyon's other master's power won't be able to seperate these two.
Little sister you are the best.