Is living with a significant other still sinful even without sex?

Is living with a significant other still sinful even without sex?
Full Question:
Is living together with a significant other still considered cohabitation if there is no sex involved? Are the two different?
Answer:
I believe you mean two unmarried people living together without having sexual relations with each other. Each of these people is unmarried even to other people; this is the assumption here. If the conditions are different, like one of them is married to someone else, then the gravity of the sin would be more severe. For the sake of this answer, let us stick to the previous assumption.
Cohabitation between two unmarried partners is an occasion of not one but two sins. The first is fornication which is sexual relations between two unmarried people. If there are no sexual relations between the two, there is still the exposure to temptation; we are supposed to avoid near occasions of sin. If one is serious about their spiritual life, one should not expose themselves to this kind of temptation.
The second sin is scandal which the Catechism of the Catholic Church defines thus:
Scandal is an attitude or behavior which leads another to do evil. The person who gives scandal becomes his neighbor’s tempter. He damages virtue and integrity; he may even draw his brother into spiritual death. Scandal is a grave offense if, by deed or omission, another is deliberately led into a grave offense
CCC 2284
When two people live together, they make other people assume this is an acceptable lifestyle—giving other people scandal and leading them to a potentially sinful life. So without even engaging in sex, this couple exposes other people to sin as well as themselves. So either way, living together is a bad idea and is definitely sinful even without overt sexual activities.
Think about it this way: is a professional juggler who has spent about three decades taking risks, throwing knives and fires up, and catching them guilty for endangering his kid in an act? I mean, he is a professional and has never missed. Let us even assume he can never make a mistake. Wouldn’t you agree (as do civil law) that endangering his child is in itself a crime?
Is living with a significant other still sinful even without sex?