exes: PLEASE help

Sarah
Is it weird that my guy still talks to his exes? A few of them. Like his old friend exes from years ago who now have new  boyfriends, i understand, but even his most recent one from a few months ago.... i know hes just trying to be friendly and like the most recent ex lives in another country, but he got a birthday card from her signed "much love xxx" the other day and i feel really shitty about it.... i knew he still talked to her on fb messenger and all and hes told all his friends and family that they broke up because she was boring and far away (i mean she was a dairy farmer....) but still; i dont particularly like him getting a card from his ex signed with love.... but were also new still and i dont want to come off in a bad way or in a way that seems like im tellingg him who to talk to and who not to talk to.... what do i do?