They wanted to adopt a kid, so they went to the adoption center in hell. When they saw you, the worker explained to them that you weren't exactly fond of them. Because Mammon kilt your mother and you thought that fizzaroli helped with it because fizzaroli used to work with Mammon. And since Mammon was a deadly sin . You didn't exactly like asmodeus, either

Fizzaroli:So we understand that you - he got caught off you grabbed a knife Where did they get a knife?!