696 is pronounced six ninety-six, not six-hundred ninety-six.
696 is an enhanced version of 69
, but altered to accommodate a third person who cannot participate. This third person's presence may or may not be known.
1. I 696ed with my parents. While they 69ed I was jerkin it in the closet. (Unknown third person)
2. My bitch came over the other day, but she was on period, so instead I 69ed with someone else while she watched. (Known and extremely jealous third person)