Thank you. On this website, I do not always get to give good news, and this is one of these times.
1) The agreement signed informally is not enforceable because (a) informal agreements for custody are not enforceable as a rule unless ratified by the court and (b) especially if they go against an established court order. Ergo, even if the agreement says 6 months trial period, the father still has the right to custody regardless.
2) The child does not decide which parent they want to live with. You can file a Petition to Modify Parent Child Relationship and his preference will a factor that the Court considers, especially if he is now a bit older. However, this is not a confirmation that the Court will agree (of course if the father will agree, then the Judge will sign off on it).
3) Ergo, I am afraid that the onus is on you to file the suit (or threaten to do so) unless the father agrees to let him go back to Texas and also signs off on the modification of formal modification paperwork peacefully. Let me know if you need a copy of the paperwork.
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