I haven't heard from a good friend for a while, I would like to reproach him playfully, but have no clue what the appropriate thing to say would be.
恥を知れ! be appropriate if said in a funny tone, or is it too strong of an expression?
Edit: some context
Forgive me if I didn't add too much context, but I wanted a generic advice more than a specific one. Though I understand in language, and especially in such a language as Japanese is, it doesn't make much sense to be context-free.
Basically, we are very good friends, both males. We travelled a lot together while in Europe; I stayed at his place in Japan, he stayed at my place; met my family. We have a very strong connection and we are playful with eachother.
We are, however, admittetly both 筆無精. And we don't keep in touch. The reason why I wanted something more than 久しぶり is because he got married and just did an announcement on Facebook. I want to do this playful scolding, but I don't want to sound too serious: of course I really care about his life, but I understand things have been hectic and he didn't have time to contact me.