We've hit it off ever since we knew each other.
我们从刚认识就很投缘。
俚语表达hit it off with sb.,意思是“to be friendly with each other immediately”(与某人很快就能合得来)。
例句:
She hit it off with Dean and soon the two of them set out on a cross-country adventure.
她和迪恩成了好朋友,不久,他俩人就一起去跨国旅行了。