He was not in fact shy, not exactly. Distracted and oblivious a majority of the time, but not shy. Ella's hand in his hair (he really did need to cut it, if he would just remember) felt good, and he liked her soft skin and soft touches.
At her making the next step, Slav got closer to her, using his other hand to cup the other side of her jaw. So that he was holding her head cupped in his hands. While his mouth opened to meet her tongue with his own.