Trust between two people is a 'two-way street'. [=trust requires effort from both people]
Communication is a 'two-way' process.
a 'two-way' street
(..) I thought you don't share food? Sure I do. Coulis? No. If I can't have your clams, you can't have my dessert. This is a two-way street. Really? Really. Now this all better be here when I come back. Yeah, of course. I can control myself. (..)2004 TvShow: Friends Title: The One with the Birth Mother Season: 10 Episode 9