Responses
I'm pretty sure they are at the seme's house going by what they show in the first panels and how the uke's asking if he can just come in.
And for some reason...I don't think is a 1 sided window (≧∀≦) so that only leaves with the possibility that anyone can see what is going on inside (๑•ㅂ•)و✧
So about the window... I'm not sure if they are at the seme's house or a hotel, but at some love hotels they have rooms where there's one way mirrors for the windows. This is because there is a kink where people like to feel like people are watching them have sex. So all anyone outside would be seeing is a reflection of themselves. Still I'm not sure about whether they are at his house or hotel. Maybe he's kinky enough to have that in his house. If not the uke is fucked.#－.－)