Two most laziest way to make netorare story, lol. In one way he just like puppet with no brains and emotions, in second he with no reason starting jerking off on how his girlfriend fucked.If it's about how the MC kno (or not) about the cucking, the dev said he plan to made 2 paths here : one in which Kirito is unaware of was is hapening (usual cucked dumb boy), and one where he found out but enjoy being cucked (usual cucked weirdo)...
I think I ended with this game.