Ex-boyfriends Father passed away

I was with my ex for close to 7 years when we broke up. He didn't handle the break up well but has since moved on and I have done the same. It has been close to 2 years since we have seen each other but his father who I was close with all those years passed away unexpectedly 2 days ago. I sent flowers to his mother this morning but do not know the correct thing to do when it comes to the viewing or funeral since my parents will be attending (they are still family friends) Any advice is appreciated.