If you are a boy, do not, under any circumstances, go clothes shopping with your mom. In fact, pay no attention to your pants with rips in the knees and plenty of flood clearance. They're comfortable. Who cares what they look like.
So, when you come home from school and notice two new pairs of pants on your bed, do not acknowledge them. Later, when your mom asks you if you saw the pants, do not commit. You aren't sure. You can't remember. You'll go up and see in a little bit. As soon as you finish playing your game.
Let your mom ask you three more times if you've tried on the pants yet. But whatever you do, do not try on the pants.
At 10pm, your mom will head for bed. Act like you're listening when she begs you not to rip off the tags before trying the pants on, and nod when she asks you to tell her how they fit. Do not try the pants on. Do not move the pants off the bed.
Until it's time for you to get in bed. Then, wad the pants up and throw them into the corner of your room.
Tomorrow, when you get up. Put on your old pants with the rip and two inches of flood clearance.
It is raining, after all.
For more on how to be a boy:
How to extinguish a candle
How to eat popcorn
How to build a blanket fort
How to find your shirt
How to wait in line
How to Butter your bagel