Although this certainly wasn't the hardest thing he had ever done, that didn't mean that there was no anxiety stirring in his mind as he waited nervously for her response, hoping that he didn't offend her by asking her to wait. Although he might have obliged her request solely based on his desire for her and the fact that she seemingly was more than willing, he wouldn't have felt right if he jumped into the relationship too fast and too much, not when he had just began to know her.
After only a few weeks, there was still so much that they were yet to understand of each other, something that he had become painfully aware of during the events that happened in Denerim and realized with a sharp dislike that she came from a culture and even enviroment that was entirely variant from his; they might as well have come from opposite ends of the scale or from completely different worlds. Among that vast list of things he didn't know (he was now making a list in his mind and hoping that he wouldn't forget anything since he didn't have anything to record said list): he didn't know if she had a good childhood or what her parents were like, didn't know if she liked humans or if she even liked being a Grey Warden -- Creator, he didn't even know what her favorite color was.
And, of course in all honesty, he was glad that he refused because then she would have felt something that wasn't exactly true. Faer was quite infatuated with Lalin and felt strongly for her more than any other woman he's ever met (in the physical, mental and emotional sense), but to say that he could truthfully solidify his feelings for love wouldn't be a genuine statement. Besides, the end result wasn't what he wanted as he traveled through this emotion of "love", it was the journey of doing it with Lalin that made it worthy for him.
He was sure that, even if she might have gotten carried away for this particular moment, it was the same for her. That was evident when she gave him her response and he was able to settle down as she reassuringly pressed another gentle kiss on his lips, no longer afraid that she might have taken his words the wrong way. In return for this, he gave her a smile that was only reserved for specific people, the one that showed nothing but a curve of love and a shine in his eyes, the kind that might as well have said, "I love you."
And in that very second, Faer realized that her reaction to his decline made him fall in love with her. Or, if not that strongly, than it was a very close inner declaration. He had never met anyone so bold and daring, so strong and stable, someone so loving and heart-warming, not even his mother could match to the sort of affection he felt from her (and neither did she match the affection he felt for Lalin) and there was nothing that Faer would have changed about her. Not even the fact that she was so strongly attached to her friends and loyal to her family, not even that she was willing to give someone the benefit of the doubt when no one else would, not even when she outright yelled and scolded someone for betraying her trust. She was, in all entirely, everything he wanted to be.
And one day, given that he could actually muster up the courage (he's done it before, he was sure he could do it again), he would tell her. But certainly, tonight -- and not for a few more weeks, in all honesty and matter-of-factly -- isn't the time.