Opting out from autofill per site option

Some site do not function very well with autofill

One of my site where I have two possible logins ( me and my wife) only shows one as autofill

I want to opt out for autofill on that site ( and some others )

No way I see I can do this

or tell me how, or add the option for each site to be able to opt out

and it seems I cannot deactivate autofill totally, it only shows ACTIVE, this is wrong

Thanks