Why shouldn’t you do what he is asking or wants sexually, sensually, erotically?
If he is an asshole. Mean, grumpy, demanding, a workaholic combined with going out/staying out at night with his friends. If he is withholding emotionally.
If he is verbally or emotionally abusive then you shouldn’t and you should get counseling and so should he. If he is physically abusive then not only should you not, but you should get out of the relationship (get help to do so and protect yourself and your children).
If it is humiliating and humiliation is not a turn-on or exciting for you. Humiliation can be a turn-on for some people.
If it is physically painful or scarring and you are not into pain or being marked.
If it is degrading or, better put, you find it degrading and degrading is not a turn-on for you. For example, facials – i.e. your husband wants to cum on your face. Some women, I don’t know any, might like that. Most, I think, don’t.
It is harmful to your relationship and marriage. Three ways or swinging can cause irreparable damage to a relationship and marriage.
The above are valid reasons why you shouldn’t.
It’s gross can be a valid reason. Golden showers and scat play are not most people’s cup of tea. This one is usually connected to degrading and-or humiliating and-or maybe even harmful to your relationship.
The below are not valid reasons why you shouldn’t:
I don’t like it. If you haven’t tried it or tried several times, often it takes several times before you know if you really truly like or don’t like something, then how do you know? It’s gross may be an exception to this and you can say I don’t like it without trying it. I think most people know they don’t like or want to be pissed on or play with poop.
It’s immoral. Outside of three ways and swinging, nothing sensual or sexual or erotic between two married, consenting, loving people is immoral.
If it’s just between you and your husband in your house then there should be virtually no limits to what you and he do together sensually, sexually, erotically. There should be virtually no limits or boundaries to which you do things to please and pleasure each other.