[cat_with_no_eyes]

at tennis, I try my best to win, but i always lose! How can I stop him winning?!

[Bored chemist]

Wait.
Once he's old you will have a better chance.

[peppercorn]

[] I was already to call the RSPCC police when I saw the title of this thread! []


You could try tying ya dad's shoelaces together or swap his, erm, court shoes for one two sizes smaller! []

[Variola]

Itching powder in his tennis shorts  []

[Karen W.]

I like the itching powder idea!  [] Spot on! [] What a sight that would make...LOL...LOL.

[Geezer]

You could make some tennis balls "googley" by injecting silicone caulk into them.

[maffsolo]

You could make some tennis balls "googley" by injecting silicone caulk into them.

Yea what a combo; itchy jocketed, unbalanced balls.
Just cut the strings in his racket
Sew up the legs of his tennis shorts to his socks 
He will need to fore foot the game

[James Carl]

Sad to know you were beaten by your father.
Though beating is not the solution, he beats you because he wants you to be the best.
In that case am lucky, my father is very loving.