"Its enough of a pain to carry the shorts around with me, let alone a complete outfit. What do I look like, a pack mule? My clothes don't just pop in and out of existence when I change---I have to carry them with me while I run. Pardon me for keeping my burden light. Does my being half-naked bother you? Jacob Black
The reasons he lacks a baju so often: 1. He doesn't feel cold so he doesn't bother 2. If he needs to phase quickly, it takes less time to take off a pair of trousers than trousers and a shirt 3. It's less weight to carry around in serigala, wolf form, and possibly less to lose 4. If he does phase too quickly and ruins his clothes, he only has to replace one pair of trousers.