A sex act some consider sordid, a Bangalore Strawberry is the process of sticking one's nose in another person's rectum. At which point the recipient farts.
The name comes from a combination of Bangalore, a place known to be dirty, smelly, warm and unhygenic (the rectum), and a strawberry, a fruit which is very red (i.e. the nose becomes red from the friction of being in such a tight space).
Man...it smells like a Bangalore Strawberry in here!