What would happen if i slapped my wiener on a cactus?

It would be very painful. The cactus spines would puncture your skin and cause bleeding and possibly infection. You could also damage the tissues of your penis, which could lead to erectile dysfunction. In addition, the pain could cause you to go into shock, which is a life-threatening condition.

Therefore, it is strongly recommended that you do not slap your wiener on a cactus.