Take the biggest, thickest banana you have and place it intact (don't peel it) in the freezer right now.
After 1 hour, strip completely naked and take the banana from the freezer. Watching a nearby clock to keep track of the seconds, push the entire banana up your asshole immediately. You will push it in as is without the benefit of any type of lube.
The total number of seconds that it takes to get the entire banana in your asshole until your sphincter closes down on the stem will be the the number of hours you will need to keep the banana in your asshole. Example: 5 seconds = 5 hours, 10 seconds = 10 hours, etc. The challenge is to overcome immediate discomfort in order to minimize the maximum amount of keeping it in for less or more than a day!
Additionally, you must roll a single die. Whatever number comes up you multiply by 3 which is the number of times you must masturbate to edge per hour. If you don't make your quota in a given hour, the entire number per hour times the entire time period you have the banana in your asshole is the total number of hours you can NOT cum, for any reason, after you remove the banana! Example: You'll have the banana in for 24 hours continuously and you roll a 6 on the die. You must masturbate to edge 18 times in each hour. If in any hour, you don't edge at least 18 times, you multiply 18 (per hour) with 24 (total hours the banana is in your asshole) to equal 432 hours (18 days) you're NOT allowed to cum!
Any hour when you have to remove the banana doesn't count toward your total time plus you must add an additional 12 hours to the total.
While you're home alone, you will remain completely naked. If you are leaving home, you may not wear any underwear. Of course, the banana remains in continuously for the entire time period!
If you want finish the dare on a special note, when you reach the end of the time limit and you pull the banana out, you may lick the skin clean before peeling it and eating the "baked" fruit inside! It might be best to remove it while in the bathroom, in case you have the urge.