yeah. I think thats a valid scenario, the Mc would want Ayumi to do something with Terraces cock.
how and where will be interesting to see.
as for me I don't care for any scene with Terrace.
but if u ask me to include him somehow I could enjoy this:
Mc suggest to Ayumi to invite a male for some sexy moments, but both are scared it can mess it up, and eventually agree that Terrace is the one, as they know him. one evening they go out for some partying and they drink a bit, during that, there will be some nice dancing and Ayumi will tease the boys. when they get home they all find themselves in Terrace bed, tired, half awakem now Mc and Ayumi start to makeout while Terrace is lying there not sure what to do, now Mc says to Ayumi that Terrace is leftout and tells Ayumi to kiss Terrace, she turns around and they do all that, after a bit she go back to Mc to kiss him again, and this goes on a bit, until shes with Terrace again and Mc start to undress her top, showing booby, that leads to them kissing and sucking her nipples. the Mc keeps undressing her until shes all naked, and they both caress and the entire of her body, they keep going and lastly they make her cum, and the end. so thats it. they go to their bed and continue on their own.
next day its all akward but laugh about it. thats it.