During the most intense moments between us, I find myself scrambling for words, or trying to recite lines from poems I don't know and perhaps "should know to date you." I won't go as far as saying that "words cannot capture you" or that "words just aren't good enough" – making a claim like that to a writer would just be asking for trouble or another argument not about us (though potentially more dangerous than one that is). Plus, saying that would mostly indicate laziness on my part. I have promised myself that I will never use that as an excuse to not write about you.
The problem comes in the lack of expertise. They call the phenomenon "verbal overshadowing," initially observed in some experiments done where subjects who verbally described a previously seen face were less able to recognize the same face again. They replicated the experiment with wine tasting, and they found that wine experts were not affected by verbal overshadowing. They had adequate wine-vocabulary.
Even after the many times lying with you, the landscape of your body remains foreign to me. I say that because every time I discover something new, something to be fascinated with: the way your lips thin when you pull them into a smile, the tiny hair on the back of your neck, the shifting contour of your back when you're propped up on your elbows. I avoid words because I want to remember all this. I want to learn the language of your body so I can recognize you; I want to be able to close my eyes and still read your smile with my fingertips.
I don't want to mistake your face for someone else's for having described you with a language I have not mastered; I don't want to risk forgetting your presence by prematurely putting you into words. So until the day I collect a vocabulary competent enough for you, you will have to accept quiet smiles and silent avoidance as temporary answers.