Two moms (possibly sisters?) go on holiday with their sons and after some drinking at the apartment they’re all sat at the table and the sons make a move on one another’s moms and fuck them, then fuck their own moms too.
Remember a vague detail about the moms waiting for them naked in the bedroom afterwards on all fours in the dark
Source: reddit.com/r/Erotica/comments/owcixl/help_finding_a_mom_son_swap_story
try r/tipofmypenis