Is there a widget or something I can go with IFTTT to block and unblock a contact?

I have a friend that says some pretty bad things about certain people pretty often and a lot of the time I am around those people while he's sending me those messages. I just want a button/widget I can use to discreetly block his texts and calls quickly, like as the person is walking up to me and will arrive in less than 3 seconds. Does that exist? Can I use IFTTT to do something like that?