How tell/ask my bf that I am going to change my relationship status on face book?

Ok, so yesterday him and I have decided to be in a relationship officially and before that, we have been seeing only each other for 3 months. My fb is still set to single and I want to change it, but I feel like I should let him know. Would it sound annoying for me to ask him if I can change it, am I even obligated to 'ask' ? Or should I wait a little longer?