It starts of as adventure, until it conditions you both, becoming a new condition of your relationship.

 When it comes to women performing oral intercourse with her husband. It is about bring a source of her capacity to love, (her lips she uses to kiss). Into communication with a source of his capacity to love, (his penis he uses to have intercourse). Thus it is about treating him special for an impressive communication of his capacity to love. 
However it can carry from ‘sexual arousal feelings’ to ‘orgasm peaking and plateau’ feelings. Making this, what started out as a communication of intimacy, into the making of a false covenant.  Here she writes a new path for him achieving orgasms, based on her rewarding him with pleasure, of her treating him special, in response to how impressive he takes care of her. And that is why he likes her and wants to be together as a couple.