If this is asking whether or not you can romance Amber & Liz without them getting mad then yes, you can. If i remember correctly they do find out if you romance both of them, Amber briefly scolds MC But says shes fine with it and Liz doesn't care.
Also the game has a "harem route," although it is vague and is still in the process of having each woman find out about the others despite having been with them for YEARS now in game.
