I can't read more than the first 3 lines of your post, but you should consult an attorney if you think you qualify as common-law married. Did he introduce you as his wife? Did he list you as a dependent on his taxes? If so, a consult may be worth it.
The really easy solution is to explain your situation to your server when you go out, and ask about their policies. I'm pretty sure they'd rather have you use the women's (or employees' if they have one) rather than any other place you'd use if the men's room is occupied.
What is the name of your state (only U.S. law)? International Custody Case, Illinois and Ireland
In this case, the mother had been a long-time resident of Ireland with the father. She has dual citizenship. Six months after their child was born, she relocated to the US against the father's...