I have read that this is commonly due to time and effort so i wondered if suggesting this would help anyone.
If you have told your wife/girlfriend that you have paruresis and the only time you get to go out into the town/city is on a weekend when you are with her, then perhaps you could go out by yourself for an hour or so before she does. For example...
Arrange a time to meet up in your town/city (say 11am Saturday), fluid load at home, then take a bottle of water out with you and arrive in town by yourself for 10am. Use one public toilet after another, drain off around 10.55am at the last one and then meet up with your other half at agreed time.
Of course, if you haven't told your other half but have told a friend that you meet up with on weekends then you can use the same method.
What do other message board readers think?