The 27-year-old singer declared they were non-binary gender in September and asked other people to use the pronouns "they/them" in reference to the musician, but Sam's mum Kate often "trips up" and says "he/him" instead.
Speaking on Australian talk show 'The Project', Sam said: "I say to my mum all the time - she will be calling me 'he and him' and she is getting angry at herself and it's OK."
Sam announced their new pronouns in a lengthy Instagram post last year after "being at war" with their identity for so long.
The 'Promises' hitmaker said: "Today is a good day so here goes. I've decided I am changing my pronouns to THEY/THEM after a lifetime of being at war with my gender I've decided to embrace myself for who I am, inside and out.
"I'm so excited and privileged to be surrounded by people that support me in this decision but I've been very nervous about announcing this because I care too much about what people think but f**k it!"
What's more, the 'Promises' hitmaker often forgets to use the correct pronouns themselves.
They added: "'I trip up too. Of course I do, I'm a human being.
"I have been called 'he and him' since the day I was born, you know, 27 years of my life, so I can understand."
However, they are still delighted when someone does get it right as it makes them feel "safe" and "seen".
Sam stated: "But it is important, you know. I feel safe and I feel happy and I feel completely seen."
Sam first heard of the term non-binary whilst on his second tour in Brisbane, Australia, after a night out.
They explained: "I had a massive night out at the end of the tour and I was drunk at 3am with my bandmates and friends in my room and I just started hearing about the term non-binary, and I'd never heard it before.
"The pronoun thing for me just felt like a flag in the ground kind of, like this is how I want to be treated by everyone."