Drink several litres of water and then either:

go for a run that takes you on a circular route starting and finishing at your house IN BROAD DAYLIGHT, and always crossing the road to get close to people you see ahead... you aren't allowed to hold it in if you need to pee ;)

or go shopping, all day. Again, no holding in...

go shopping with butplug in..

put 10 icecubes down your underwear, give yourself a wedgie,duct tape the legs and waistband shut, then drink a liter of water. Now go to the mall and walk around like that for an hour at least.

Go to your local store (be it a big mall or a corner store - whichever is closer). Find a secluded part of the store and start to rub yourself, for 1 min. If someone comes by you must continue, but turn away so they can't see your front. Once finished, place your hand down your pants and walk out the store. Find a secluded spot outside and wank, but keep it in your pants...

Get a buttplug or a dildo up you ass.
Then go for a walk.
During your walk, you have to remove the buttplug/dildo from you ass. (You may hide. Do it while walking, if you are daring)
You are only allowed to go back home, if you managed to remove it.

the mall
 

Go to a mall bring a maker and a plug with you.. go to a restroom and do your self anally with the maker for 12 strokes then insert your plug .. now make one lap of the mall with the marker in your teeth.

Male into crossdressing

Write all over your body in pen and go out to a mall and carry on our usual day but no one would realise you have discriminating words over your body!

Wear female underwear under your normal clothes while out in public.

mall
 

Make a underwear out of ducktape and take a walk in the mall


Male into crossdressing

girls underwear + tights under your normal clothes for 3 days

You must rub yourself (directly, not through clothes) 10 times next time you're out at a shop. Each time must be 10s long. If you pull out before 10s, it doesn't count and adds 10s to another time.

2 eggs in underwear for a whole day

Order something from a fast food restaurant, and when no one's looking, shove it into your underwear.

wear womens underwear (and bra) all day

put something inside your vag and keep it in for 4 hours. doesn't matter what size or what it is. but something has to be in for four hours.