Absolution question

I haven't seen any reviews that commented on the title. The title puzzled me. Who is seeking absolution? And what for? Presumably Tricia and Rainey are seeking something in recounting their past years, but is it absolution? They don't seem repentant nor do they acknowledge much wrong. They look back and kind of think "it was what it was." Maybe some minor regrets but hardly acknowledging they need to be absolved. Is McDermott absolving them anyway? She quotes Graham Greene - If only there was someone to whom I could say I was sorry - I don't think the characters in McDermott's book feel this way. Maybe Dom would, but he's made his amends.