Shit, I smoke in my parents house all the time. When they're asleep, I'll pack a bowl at the computer or light up a J on the couch. I just open a window and blow in that direction. And don't worry about people seeing smoke. If it's dark out and this late, I doubt people will be standing right outside your window and looking to see if your getting stoned. Nah, you'll be fine. If you're that paranoid take your hits next to the window and blow out there, the smell won't do anything then 'cause you've got no smoke in the house. Oh, and when you light your bowl up make sure to pack the burning weed down with your lighter to put it out. Conserves weed and makes less smoke for less smell.