Question ?

So I went food shopping with my best friend who has a boyfriend of 5 years

and she said that she was cold and asked to borrow a hoodie. The only hoodie I had was my boyfriends and she asked if I mind if she wears it and I said she could wear it for now. Do you think it is fine that she wore it and he wont care or think its weird? And she is always saying how i have nothing to worry about when he goes to parties bc she doesn’t know what i see in him she doesnt fine him attractive why does she say that and say how shes happy her bf dont go to parties like mine does. She is a bit immature but i dont know how to tell her i dont like that she says not nice things about my boyfriend i love him very much and don’t appreciate it