Nedarim 15: Vowing to Abstain from Sexual Intercourse with one's Husband or Wife

When a person makes a vow that goes against Torah law, it cannot be observed.  Further, one should be punished for "profaning his word" as described in Numbers (30:3).  Today's daf considers a number of situations where a complex, conditional vow is taken.  When are those cases considered to be vows; where one might be flogged for the transgression?  

If a vow is conditional on timing - "I will not benefit from this food tomorrow if I close my eyes today", and person taking the vow eats the bread on the same day the vow is made, has he transgressed?  He has not transgressed the vow, but he has profaned his word.  If a man vows that his wife will not benefit from him if she visits her father's home before Pesach, does she get flogged for breaking that vow and visiting within the time limit given?  

Most interesting are the examples that involve couples who make vows affecting their sexual relationships.  But husbands and wives have different obligations regarding marital relations.  If a husband vows that he will not have intercourse with his wife, the court will order him to reverse his vow, for she has the right to undiminished food, clothing and conjugal rights (Exodus 21:10).  But if he vows not to derive pleasure from the intercourse, his vow can be upheld.  And because that wording allows the vow to be upheld, the rabbis allow even other wording, including the  otherwise meaningless "vow to not have intercourse with my wife" to represent this second meaning.  Thus a husband is allowed to stop having intercourse with his wife.

What if a wife vows that she will not have intercourse with her husband?  Again, the court will order her to continue marital relations as she is obligated to conjugal rights (Exodus 21:10).  However, if she vows that the pleasure she derives from intercourse is prohibited to her, the court will uphold her vow.  She is assumed to find pleasure in intercourse and "one may not feed a person that which is forbidden to them."

It seems that a woman who had access to rabbinic texts would be able to avoid intercourse with her husband if she were to find him distasteful. Because of the assumption that women find pleasure through sexual intercourse, regardless of their relationships or level of connectedness with their husbands, women could claim that they wished to deny themselves that pleasure in the form of a vow.

Did women want children so desperately that men were under the impression that women were interested in sexual intercourse with their husbands at every permitted opportunity?  Or did women enjoy intercourse in a different way in antiquity than today?  Or, most likely, were women's sexual desire not within the realm of the rabbis' expertise?  Again I wonder whether intercourse was practiced simply toward procreation or if it included more varied activities that might provide women with more of the pleasure that the rabbis describe.