The ‘offending’ phrase is “Yeah, like when my guinea pig ran away, my mum’s told me he might come back.”
The idea that this refers to two mums has gone viral - but mum in this context in casual Australian speech more usually means “my mum has told me he might come back.”
Discussion here: https://notthebee.com/article/bluey-had-its-first-lgbt-moment-and-the-wokies-were-really-happy
So is it mums or mum’s?? Punctuation is key here.