(a) “Suit affecting the parent-child relationship” means a suit filed as provided by this title in which the appointment of a managing conservator or a possessory conservator, access to or support of a child, or establishment or termination of the parent-child relationship is requested.
(b) The following are not suits affecting the parent-child relationship:
(1) a habeas corpus proceeding under Chapter 157;
(2) a proceeding filed under Chapter 159 to determine parentage or to establish, enforce, or modify child support, whether this state is acting as the initiating or responding state; and
(3) a proceeding under Title 2.