Abstract: Even against the opinion of the national authors, the Supreme Court considers the non-formalized cohabiting relationship as an opposable title against actions of precarious. To justify his position, he uses at least two criteria: the existence of children in common and the authorizations of the owners. The idea behind this work is that these criteria do not prove to be adequate since they do not allow the existence of an obligation of the owner to tolerate the use of his thing the defendant does. Consequently, cohabiting relationships do not constitute an opposable title in the face of precarious claims under article 2195, paragraph 2°.