"My little eel-pie of love"
When my sister and I were children my parents used to refer to each other as mum and dad in our presence in line with what we called them. Perhaps you heard something similar to that??
No Mum means Mom..A term of endearment is something like awright doll (Scottish for how are you doing?) or awright bawbag (again Scottish for How are you my friend?)
Ah he might well have been saying ma'am then if he was a Brit.