There is a group of us that have been friends since we were kids, all had quite difficult childhoods and are really close.
The last 2 years or so best friend's girlfriend has insisted on coming to every single meet up, I mean literally best friend can't even come out for a coffee without her. We all have other halves and we do all bring them sometimes and we all get on but it just seems very controlling. He never meets up with male fiends alone either so I don't think it's an insecurity thing.
Tonight my DH had the kids, other friends partners weren't coming for various reasons (work, didn't fancy it, other plans etc.) So friend who had arranged meeting up and said lets have an old days sort of night, no partners or kids. Best friend turns up, oh GF got stroppy about me coming out without her, then she spent the whole evening getting stroppy every time we joked about old times or mentioned old school friends etc! Why? she goes out with her mates, why do they need to be joined at the hip?