腹を割って話す

はらをわってはなすharaowattehanasu

expression · godan verb

1. to speak frankly
2. to speak unreservedly
3. to open up to each other
4. to talk candidly
5. to speak by laying everything on the table
6. to talk straight from the gut
7. to have a heart-to-heart talk

Study it in Yanamino