I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear that this happened.
Your fiance has a right to insist upon a DNA test to prove that the child is his. if it is, it's not a defense that she'd had her tubes tied, even if she lied about it. It also wouldn't be a defense that they only had sex once. If the test shows that he is the biological father, he will be responsible for child support. But if he doesn't go to court, the judge will rule against him automatically, and a support order will be entered against him. The order will start accruing interest, and she can start trying to collect it. It's generally much easier to avoid getting a court order in the first place than to have one removed after the fact (and that's not to say that either is easy). These laws are written in the way thought to be most beneficial to the children involved, so they do not favor the alleged father.
If it is impossible for him to travel to Texas for the court date, he can hire a local attorney in Texas to attend on his behalf. The lawyer can take steps to get the DNA test. If it comes back negative, the case can be dismissed. A good place to see reviews from former clients is www.martindale.com.
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