Miranda has her own plans about this... while John is very interested in Lara, Miranda wants something else, something perverted, sex with Lara and Mc and maybe with her husband swing... she doesn’t care who to fuck with, as I understand it... I went the route of Lara jealousy and Lara cuckqueen, there Miranda looks like she wants to join Mc's sex life or Mc/Lara's...
So I guess while John is trying to fuck Lara, Miranda will already be getting naughty with Mc hot_scene... But we shouldn’t rule out one more thing, maybe Miranda wants to fuck Lara, these are also quite possible options