Sex or marriage are not individual cases and everything is mutually dependent.
So much interlinked are things that like a diamond needs to be polished from each side and the persons need to improve each aspect of mind and body as well as social spiritual aspects too. The thirst for sex or addiction comes from the desire of a multi-faceted union from two to one, this aspect is the real crux of getting full satisfaction from sex.
Physically try to maintain good throat, mouth, genitals and body hygiene and health as "smells" can totally put off a person may be forever. Also lack of "exercise" is the main cause of lethargy, disinterest, weakness, dullness, physically, mentally, socially and sexually too.
Thirdly "habits" must be clean, disciplined, sober, romantic and attractive and "addiction-free" and not repelling a person totally, such as the way you talk or walk, look, eat,sleep, sit, share, dress, interact etc.
Fourthly "communication skills" matter the most as lack of proper emotion, tone, words or gesture or attitude etc can almost kill a person's interest in the other person leave away sex.
Fifthly too much of anything spoils a lot in many relationships even of love,attention, caring, sex etc
So let's learn limits of sex or marriage relations and improvise day in and out and clean up any lacunae anywhere.