Bf going to house patty where his ex crush will be present

Advice over letting bf go to a party with his ex crush

Me and bf of 1yr had an argument . He wants to go to his friends house party where his ex crush will be present and he used to like her a lot and she had publicly rejected him several times yet he still liked her . Even his friends there have disrespected me many times before. I have simply asked him to not go there cuz I am not comfortable with it and said both of us can go on a date instead . Am I being too controlling or toxic? And btw I am not invited here