It is the act of having sex on the balcony of a hotel in front of the external air conditioning vent. The guests on the inside of the hotel room will be able to smell the ass (sex).
After getting killed 126 times by the same enemy on the same level, Little Bobby whent spleen venting on his cat, and as a result was sent to a psychiatric institution.
or
Robert vented his spleen by smacking his sassy girlfriend in the same mouth that she used to talk back to him. He later joined little Bobby at the Institution.