The way you describe him, it really does sound like you and your son are much better off without this guy. Unfortunately, it's not going to be that easy. The circumstances you've described sure sound like a probable common-law marriage to me. The test on that is that you have to be living together, consider yourselves husband and wife, and hold yourselves out to others as being husband and wife (so did you introduce each other to new acquaintances as being spouses or something else, did you file taxes as a married couple, sign a lease as a marred couple, things like that). If you are "common-law married" that counts just the same as "legally married" in Texas, and he cannot marry this other woman without committing bigamy.

Paralegals do not always know quite as much about the law as they think they do, in my personal experience, and it sounds like she's convinced him of a number of things that just aren't true. Child support and the right to a father-child relationship are your child's rights--not yours. The court will not let you agree to no child support just because he wants to move on. If you have a documented recent history of domestic violence, the court must consider that when making custody and visitation decisions, to minimize any potential danger to your son. Supervised, restricted visitation is the usual solution to that situation. If he doesn't want to see his own son, then perhaps something could be worked out so that he could see his grandparents instead (the specifics may depend on how stable and trustworthy they are). Regardless, he'll need to pay child support--neither you nor he have the option to just waive that. I'm sure that the attorney you're seeing Friday will have more constructive suggestions for you, but please just keep in mind that while both you and he might rather just delete him from your son's life, your son still needs a father, to whatever extent he can get one. I'm not one to gamble, but I'd be willing to lay down some serious money that if he does somehow managed to legally marry this woman, it won't last for long, so try not to stress too much over that.

My only other suggestion would be that you do whatever you can to put together as much evidence as possible for your attorney an advance--any documents the two of you signed together as husband and wife, a list of witnesses who consider you to be married, evidence (emails, texts, etc) about his statements that he doesn't want his own child and that this woman seems very hostile toward your son, evidence of the domestic violence (judgments for any convictions, offense reports, ER records, and so on), and records regarding any property you have that will need to be divided. Good luck--I hope things calm down for you and your son.