Back Flowing 

A form of enema play and/or BDSM activity whereby an enema is administered by an individual to a willing partner. A standard, over the counter, saline solution enema with nozzle delivery system is utilized. When Back Flowing, the enema nozzle is inserted into the anus and the solution is discharged deep into the recipient's bowel for pleasure. Contrary to normal enema administration, in Back Flowing, the nozzle is not removed from the anus. The nozzle remains inserted into the rectum while the enema solution is held by the recipient. Once the recipient is ready to release or given permission to expel the contents from their body, the bowels are loosened and the solution is then forced or back flowed into the original enema solution bottle.

Frank's girlfriend was into water sports as well as some kinky BDSM involving enema play. She enjoyed the full feeling in her bowels and ultimately the release. She recently begin incorporating Back Flowing into their play. They both enjoyed watching the wet and wild outward flow.

Back Flowing by Eaton Holgoode May 7, 2015

Backblowing 

An oral sex position where a man is on all fours and his penis is pulled to his rear (through his legs) and fellated from behind him.

Sunny was backblowing him while fingering his asshole.

Backblowing by Slangeek February 26, 2010