Count to 21!

I love this game!

Ok, rules:

One person says 1, 2, or 3 numbers in order, so they can count up up to 3 numbers:
eg.

Person 1: 1 2

The next person can count up to 3 numbers but adding on the the others:

Person1 : 1 2
Person2 : 1 2 3 4 5

And it keeps on going.

However, the person who says 21, whether theres more than one number or not, loses, and its started over again.

Rules:

No decimals
No skipping numbers
Add a space/comma inbetwwen numbers.

Have fun!

Ok, start:

1, 2

I don't get it.

How can you not get it? Ill explain it nice and clear:

1 person starts at 1 and counts up. They can count up to 3 numbers.

Person 1: 1, 2

Here the person counts up 2 numbers, but he could of counted up 1 or 3 instead.

The next person also counts up. They can count up to 3 numbers BUT It has to be where the last person left it:

Person 1: 1, 2
Person 2: 1, 2, 3, 4, 5.

Then the next does the same.

The person who has 21 as one of there numbers loses, and they have to start over. Get it now?

Ok:

1, 2.