OMG the entitlement of some MEN.
Women find themselves a cosy little FEMALE ONLY chat group, for support, and laughs, and tears, and to share stories; and a big fucking hairy arsed bloke has to muscle in. Drives me fucking batshit! 
@AuthenticVoice I would, as some posters have suggested, cancel it and start it up again on a different day, and keep it more of a secret.
Slightly different slant, but some years ago when I first came to this village, a woman here had a 'ladies group' that she held in her big 6 bed house, that had lots of living space. She held it in the huge 26 X 20 foot lounge, and around 20 to 22 women used to go to it. I joined around summer 2014 after being asked to it. (It had been going for about 3 years when I joined...)
6 months or so after I joined, a woman who recently moved to the village overheard me chatting in Church to someone, and this woman started discussing it, and asking if I was going on Thursday This woman pushed her neb in, and asked 'oh can I come?' (Cheek!) I said I would ask the leader/host, which I did, and she said 'er yeah OK then.' I felt so awkward asking, and I'm not sure she wanted anyone else joining.
After 5 or 6 weeks this new woman started asking if her (male) partner could come. 'He would enjoy this!' she said excitedly. The host said 'no, it's a group for women.' The woman said 'oh but there isn't one for men!' The host said 'maybe he could start one?'
Long story short, the woman kicked off, said the host was being very sexist, and actually 'breaking the law' by not allowing a man in. Fact was, it was the woman's private home, and she was inviting friends. It wasn't official, so she wasn't breaking any law. (I don't think!!!)
But the woman hosting it was so worried about legal action being taken against her, that she cancelled the group, and never had it again. She had 2-4 friends around for coffee now and again after a few months, but the big group never resurfaced. All because of this stupid cow who was threatening to take it further if her male partner couldn't come to this womans friendship group!
I did feel a bit responsible, but the host said, if anything, it was the fault of the other woman in Church, asking me if I was going to 'Elizabeth's' house for the ladies group on Thursday. I never mentioned it. She did. Also, the host could have said no to this woman. Said the group was full or something.
But yeah, tl;dr, this woman virtually inviting herself, ruined the group, by demanding her male partner comes to this female only group, and saying she'll have to have a word with someone - and take it further, as she wasn't happy with the sexism/exclusion.