You'll have to go easy on your dad. He's been told, like many others, so many bad things about marijuana. Perhaps you can keep it underwraps and in time continue on living in a healthy, normal way and then after a good long time has passed bring up the conversation again. Time reveals all and if he sees that you're not going to turn into some punk/monster or enter a gateway into all kinds of other drugs and trouble he'll be more persuaded to accept your side of the coin. My parents absolutely despised marijuana and no amount of arguing could persuade them otherwise....but as I grew up and maintained a healthy, happy and productive lifestyle they eventually began to realize that mary's not so bad. Good luck and Peace! Oh yeah, and remember that you dad loves you and only wants whats best for you so be patient and avoid conflict with him at all costs....slow and steady wins the race.....you've reminded me of something.....

Scribbled on a bar bathroom's wall:

I f#@ked your mother

Written below it:

Go home dad, you're drunk....lol