Muns

It is like swearing on your mums life, but instead, a way to get around it.

"Bro did you fuck the dog?" "Muns life I didn't"

Swear to cod

Swearing on God, but instead Cod, to make it seem like you said God.

"Aye bro did you take a sip of my drink when I wasn't looking?" "Nah swear to cod I didn't"