If you present yourself as being married, you could run into problems with bigamy laws. If you call your roommate (and wife) a partner, then you should be fine.
Non-Monogamous Discourse: Non-Monogamous Families and the Law, Part 44: Summary of Texas Laws
This link goes back to 2011, and may be outdated now. You might check the polyamory website forums to ask people who live in TX if they have more info.
Specifically, "Non-dyadic non-monogamists should show a great deal of care for their public image, due to the purportation clause in bigamy ..." It appears that not living together would avoid most of the problems you could face. Or, move to Nevada!