Sorry to Have Kept You Waiting
The show opens seeing the 2 pillars who got beaten in jail, and 2 other pillars talking to them. One is Lamia's mom. They then cut to the main gang who are tired from playing video games. Shiro acts as Lamia while talking to En. He speaks like a ditzy schoolgirl, but En buys it.
Aired 18/12/2011EP 47 - Sorry to Have Kept You Waiting
2011
Beelzebub
Oga Tatsumi is a first year student in Ishiyama High, a notorious school for delinquents. One day he sees a man floating by, and the man suddenly splits in half to reveal a baby boy inside!
(Source: Crunchyroll)