Maybe he had too much birthday cake at daughter North's party?

Kanye West retreated to his Hollywood Hills home for some quiet time after spending the weekend celebrating his daughter's first birthday with wife Kim and the rest of the Kardashian clan, and when we caught him leaving his abode, he appeared to be in a grumpy mood as he chatted on his cell phone.

Maybe Yeezy was pissed because he's packed on the pounds and wasn't happy with the way he looked in his cutoff sleeve muscle tee? The Louis Vuitton Don managed to hide his weight gain rather well, though, by distracting us with his massive gold chains!