(a) A biological or adoptive grandparent may request possession of or access to a grandchild by filing:
(1) an original suit; or
(2) a suit for modification as provided by Chapter 156.
(b) A grandparent may request possession of or access to a grandchild in a suit filed for the sole purpose of requesting the relief, without regard to whether the appointment of a managing conservator is an issue in the suit.
(c) In a suit described by Subsection (a), the person filing the suit must execute and attach an affidavit on knowledge or belief that contains, along with supporting facts, the allegation that denial of possession of or access to the child by the petitioner would significantly impair the child's physical health or emotional well-being. The court shall deny the relief sought and dismiss the suit unless the court determines that the facts stated in the affidavit, if true, would be sufficient to support the relief authorized under Section 153.433.