Looking for story where friends swap their mothers

Hi,

I am looking for stories in which best friends have lust towards each others moms and they are okay with it. Need not be incest. Would love if the women in the stories have big butts and if there is asslicking, assworship involved its great too.

Contrasting's MILF List series sounds like it would be relevant to your interests.

IIRC, so would Thinking Horndog's The Pact, though you'd have to look elsewhere for that.