My pony mare lost her long time companion this summer and wasn't doing well on her own so I put my retired gelding in with her. She has never been much of a hussy before but it has now been 11 days of cohabitating and she is still squirting and squealing all the time. The gelding thinks she is just nuts and wishes she would quit following him around and being weird. They are getting along otherwise. Will she ever go back to being the sassy, don't mess with me pony, that she used to be?
All the mares are going through fall transition this time of the year - totally normal behavior. You probably just notice it more because your mare has a big hunk of man meat that she wants a piece of. She'll calm down in a week or two!