My question involves a child custody case from the State of: Texas

My wife has a child with her ex-husband and when they got divorced 4 years ago, their decree restricted her daughter to Denton County. Now, we have outgrown our home, had two children of our own, and both work in Tarrant County. We filed for the modification to have this changed to include contiguous counties based on the understanding that this is fairly common, but he has now counter-petitioned for full custody. Should we drop the case, and stay in Denton county, or do you think he is just being difficult and trying to bully us in to giving up? Thanks in adance for any feedback.