More bent than a nine bob note

So my dear mum refers to her line manager as "more bent than a nine bob note." I just roll my eyes every time. She worked with another openly gay woman. They were excited about attending the pride festival. And my dear mum inadvertently burst their bubble with a covert homophobic response. My dear mum said " I thought you all (gay people) wanted to be seen the same and equal as everyone else? Why do you want to stand out? I think a parade, where you want to shout out you are different goes against wanting to be equal. " I can only imagine how taken aback the women would have felt and if it were me I would have been fuming. I had to grow up with all the b.s.