Personally, I find it very offensive to be referred to as 'the wife', as if I were the table, the chair, the bit of mud on the carpet... The only time I heard Manitas introduce me as 'the wife' it earned him a slap upside the head. I didn't introduce him as 'the old man' so I should be afforded the same respect.
I know I refer to Limpit as 'the child' but I never introduce her that way. Besides, she likes it. She's weird.