My spouse feels turned on and masturbates while intimate and has sex and cuckolding with my best friend

My spouse becomes aroused by the presence of my friend who masturbates alone. What I find shocking, she is much wilder than younger girls, and she continues intimacy with him behind the curtain, raising a veil in front of me to show more skin and bare herself to him in various positions as if we are in a living DVD during the next action.