TX Can he use a lawyer that represented me?
You'd need to be more specific. If the attorney represented you on a speeding ticket, for example, there wouldn't be a conflict of interest. OTOH, if the attorney has access to any significant personal information, there might be.
So when did he represent you and for what?
If there's a conflict, I don't think your husband can be penalized. It's the attorney who is doing something wrong. The solution might be as simple as sending the attorney a note reminding him that he represented you and that you consider it a conflict of interest for him to represent your husband. You might even send a copy of the letter to the state bar if you're sure it's not an innocent mistake.