non c'è due senza tre: 物事は二度あることは三度ある、という意味のイタリア語のことわざ。良いことにも悪いことにも使われる。
英語の意味
bad things come in threes (unfortunate events usually occur more than twice) / good things come in threes (fortunate events hopefully occur more than twice)
First the phone broke, then the washing machine failed: bad things come in threes, so I decided to do a complete check of the house before anything else happens.