1) Sculpt the hedges into anatomically suggestive shapes.
2) Follow a few paces behind him, spraying everything he touches with a can of Disinfectant, claiming that you know where his hands have been.
3) Challenge Finny to mow the lawn with scissors.
4) While he's taking a shower, burst into his bathroom with a camera and proceed to say in a weird accent "Work it! The camera loves you!" Take pictures and show them to Grell and Mayrin.
5) Tell Sebastian that Grell and Mayrin are fighting over the Sebby porn.
6) Teach everyone in the house Morse Code and have conversations with the others loudly in front of him.
7) Do your best to sneak up behind him and when he gets startled and asks where you came from, begin to explain "Well ya see Sebby, when a Mommy and a Daddy, love each other VEEERRRRYY much! OR When a daddy and a daddy adopt (or a mommy and a mommy)..." Continue until he gets disturbed/feels awkward and tells you to stop.
8) Introduce him to the world of Sebby/Grell yaoi fandom.
9) Read the young master yaoi Sebby/Ciel fanfics for bed time stories.
10) Shave a cat and hand it to him, claiming it's a Christmas present. Works best if it is several months away from December.
11) At dinner, convince Ciel to demand an extra seat, plate of food, and drink for his imaginary friend.
12) Buy him a Chihuahua and train it to bark when ever he says the word "The".
13) Tell Mayrin that Sebastian wants a strip tease.
14) Tell him that Grell wants to be his valentine.
15) Give Grell a Sebastian sex doll!
16) Dress up like Grell and glomp him.
17) Call him "Bassy" or "Sebby".
18) Steal and hide all the forks and knives so that he is forced to use the spoons in combat.
19) Replace all the silverware he uses to fight with plastic utensils.
20) Put a dog treat in his pocket and send a bunch of dogs after him.
21) Dress up as Ciel and "order" him to do the CaramellDansen.
22) Tell the servant's that it is Sebastian's birthday and ask bard to help you make the cake, telling him it's ok to put firecrackers in place of candles.