TexMex involves a lot of spice and chili peppers. Real Mexican food in Mexico does not. That's why your husband found it to be bland.
There are places in Houston where you can get authentic Mexican food. Most people who love TexMex (including me) don't much care for authentic Mexican because it does use similar ingredients but without the spice which, for my money, is what makes TexMex so good.
I would guess that there are very few places in the world outside of Mexico which serve authentic Mexican cuisine, and many which serve some localized version of it. Which is why there is TexMex, CalMex, NewMexico-Mex, and who knows how many other variations.