Cigarettes and Alcohol and Rollerblading (S02E08)

Ted and his friends decide to participate in a Lent challenge where they must give up various things, only to realize that it's much tougher in practice than it sounds. Father Jack manages to stay sober for the first time in ages, but both Ted and Dougal struggle to maintain their commitments. To help them stick to their promises, Ted brings in a nun to oversee their efforts. However, she proves to be incredibly strict and sadistic, leading to chaotic and humorous consequences.