Sextubate, derived from the word intubate - which is to place tube in trachea for the purposes of establishing airway and ventilating. Sextubate is the act of placing penis into trachea to block airway during a blowjob.
To go to the restroom, informing everyone you intend to take a shit, and remain in the restroom for an extended period of time while actuallymasterbating
Scott: Where is Kevin?
Andy: Oh he is in the bathroom, has been for 20 minutes, said he was taking a shit.
Scott: Oh, he must be going to shiterbate.