Tex. Family Code § 160.637

(a) Except as otherwise provided by Subsection (b) or Section 160.316, a determination of parentage is binding on:

(1) all signatories to an acknowledgment or denial of paternity as provided by Subchapter D; and

(2) all parties to an adjudication by a court acting under circumstances that satisfy the jurisdictional requirements of Section 159.201.

(b) A child is not bound by a determination of parentage under this chapter unless:

(1) the determination was based on an unrescinded acknowledgment of paternity and the acknowledgment is consistent with the results of genetic testing;

(2) the adjudication of parentage was based on a finding consistent with the results of genetic testing and the consistency is declared in the determination or is otherwise shown; or

(3) the child was a party or was represented in the proceeding determining parentage by an attorney ad litem.

(c) In a proceeding to dissolve a marriage, the court is considered to have made an adjudication of the parentage of a child if the court acts under circumstances that satisfy the jurisdictional requirements of Section 159.201, and the final order:

(1) expressly identifies the child as "a child of the marriage" or "issue of the marriage" or uses similar words indicating that the husband is the father of the child; or

(2) provides for the payment of child support for the child by the husband unless paternity is specifically disclaimed in the order.

(d) Except as otherwise provided by Subsection (b), a determination of parentage may be a defense in a subsequent proceeding seeking to adjudicate parentage by an individual who was not a party to the earlier proceeding.

(e) A party to an adjudication of paternity may challenge the adjudication only under the laws of this state relating to appeal, the vacating of judgments, or other judicial review.