C
Having asked about changing the locks when husband left and got his own place does it make a difference that we have a joint mortgage and he has a new lady friend?

Yes, it makes a difference.

He is an equal owner and cannot be barred from the property until you obtain a court order prohibiting his presence or obtain a divorce in which he is removed as owner in the property settlement.

As I stated in my previous answer, you can change the locks, but he can legally break in. It's his house, too.

That he has a lady friend is of no consequence to his ownership of the property.