I am delighted to have inspired you--and boy, you put this up fast!

Conclusion 1: Sam is a clothes-horse :)
Conclusion 2: How on earth is it possible any season one shirt fit Jared in season 5??? (On the other hand, there is the Dean shirt featured in 'Afterschool Special' season 4 that teenage Dean wore that showed up on adult Dean later...I guess the ability to increase size is part of the Winchesters' magical ability to get out blood and repair holes in their clothes.)