Kinda challenge, more of a bunny

I have this picture in my head of Spike walking up to a motel room on the outskirts of Sunnydale, intending to use it to rest for the day, and when he's passing a room, happens to look in the window and sees Xander, on his knees, getting some from a strange guy---then he hangs around long enough to find out Xander gets payed for it

Blackmail insues