One can’t spoil porridge with butter.
More Russian Proverbs:
However much you steal from your state, all the same you won't get your own back.Russian
You cannot break a wall with your forehead.
Russian
If you are a host to your guest, be a host to his dog as well.
Russian
Know friend when trouble.
Russian
The cat with cream on her whiskers should have a good excuse ready.
Russian
An unsolicited guest is better than a solicited one.
Russian