K, this is a complete over-simplification, but a woman's 'currency' is her looks/sex-appeal and a man's is provisioning/protection. The institution of marriage essentially shackles the man to the woman and since he's going to provide for himself anyway, she no longer has to 'perform' unless she 'feels' like it. Men are far more 'duty-bound' than women and for some stupid reason we default to thinking if we do this for her, she will do that for us...sorry, doesn't work that way. There's no way you can 'negotiate' for her desire...she either feels it or she doesn't.
One of the most pathetic things I see far too often, are men essentially 'begging' their women for affection...if it's not her idea, then as a man, you have to employ different tactics