Definitely not cheating because of the condom and she leaves her weddring ring on. However, I do see her reaction of her falling in love with the stud.. so she's definitely swaying. A very ideal hotwife for someone like me.
Clearly this wife has participated in the delivery to another man by her husband, her naivety and innocence is very clear, she really feels the strange man inside her and sends a slight smile to her husband, very possibly it is the initiation of her to be shared with all those that her husband indicates.