Kyle was shocked by the gesture Calista had shown him because he never expected her to reciprocate his energy but this confirmed that this was becoming a serious thing.
However, his earlier conversation with her regarding Jane and Ella told him that she was one to accept him having multiple women as long as he didn't neglect her.
Or he would have gotten a more violent reaction from her when he told her he did leave with some women.
Calista's main concern was to maintain her spot in his life even if he did have other women.
She knew how these things worked so it wouldn't surprise her nonetheless.
She left Kyle alone soon after and allowed him to have the day to himself just like he planned to.
He hopped on his gaming console and played some games, most notably God of War: Ragnarok.
This was one of his favourite games because it symbolized Kratos' journey from a brute to a gentle god.