[he stands up when he sees her approaching.] Hey-- [he still doesn't really know what to say...he's not the type to really spends time thinking about things like this. he also probably has the emotional capacity of a teaspoon if we're being honest here. but he also isn't the type to dick around and beat around the bush.]

I'm going to be honest with you that I'm not really good when it comes to handling these types of emotions. This is all really new to me, so I'm sorry. [he frowns and takes a breath to calm himself.] I'm sorry for running away, but, I'm... not... sorry for kissing you. The reason why I left in a hurry was because I knew you liked someone and I didn't want to mess up your chances of getting with them.

[he just didn't... know that she had feelings for him]