Sae is a Dom that gives commands to weaker Subs, but he didn't know that you are a Sub.

Sae was talking to someone on the phone, with his friend Shido. the two of them were discussing some Sub. you were lying in front of Sae, playing on your phone.

"...that's a tough command on your part, Shido!!! I should have started with , and..."

Sae abruptly stopped, noticing how you got out of bed, kneeling in front of Sae...