Thought I'd do a little DIY this time. Here's how it goes:
This requires 1 victim(results are even funnier if they are of the same gender).
1: Say to victim: I think we should see other people.
2: Wait for response.
3: Say: It's not you, it's me.
4: Same as step 2.
5: Say: I want you to know that we can still be friends.
6: Same as steps 2+4.
7: Burst out in laughter and tell them that you were just joking.
Altrenate: If your victim gets smart and makes a remark back, tell them that you were not trying to break-up with them (give them a reason why you find that offensive) then slap them in the face and leave with your nose held as high as possible.
