Tex. Rev. Civ. Stat. art. 6137
In a suit against such company or association, in addition to service on the president, secretary, treasurer or general agent of such companies or association, service of citation may also be had on any and all of the stockholders or members of such companies or associations; and, in the event judgment shall be against such unincorporated company or association, it shall be equally binding upon the individual property of the stockholders or members so served, and executions may issue against the property of the individual stockholders or members, as well as against the joint property; but executions shall not issue against the individual property of the stockholders or members until execution against the joint property has been returned without satisfaction.
Tex. Rev. Civ. Stat. Ann. art. 6137