Ex-boyfriend? Ex-boyfriend?? Ex-boyfriend??? (S01E06)

Momose decides to change phone models after dropping his smartphone in a fountain. He then gets a call from his former boss, Kurono, who was supposed to be blocked, and panics. Worried about Momose, Shirosaki decides to personally see him home. Until now, Momose has been terrified to face the scars of his past. But after hearing a heartwarming and personal story from Shirosaki, Momose gains the courage to face Kurono. What suggestion does Shirosaki give to Momose who decides to make the phone call?