Depends on the relationship.
Marriage? No. Well, maybe. Depending on what "not good" means. If one person wants something on one extreme, like BDSM, and the other only wants gentle with wine, soft music and soft touches, I don't think that's going to work.
I am not sure if in marriage a person needs to stay in a sexless relationship. That would be a deal breaker for a lot of people. Intimacy is important. Sexual compatibility I guess needs to be unearthed during dating. I see people go from first date to serious relationship over night that they skip this. 3 years later they are then so unhappy. I never would think sex should make you walk away from someone you love but I guess it is a judgement call and about what matters to you. I have a feeling a lot of long term couples ask themselves these questions.
I don't think anyone should stay in a sexless marriage if they want sex. I guess the way I'd say it is if one person wants something sexual that the other person doesn't want (whether sexless, BDSM, or something else) it sounds like it could be enough of a deal-breaker that they would be justified in ending the marriage. Sex is particularly important to men, I think, in that they get a lot of their sense of self-esteem from whether a woman wants to sleep with them. (With women, it seems like the other way around, only when they feel good about themselves do they want to have sex, but with men it seems like they use someone's willingness to have sex with them to buck themselves up self-esteem wise.) I don't know how a guy not getting sex from his wife would stay, in the long term.
Yes its okay to break up , Sex is very important in a relationship