Just an assumption, but it's probably an untranslated Japanese sound. I usually see it translated as "jeez", or something like that. Say it multiple times, and you're saying "ma ma", or Mama.what is Ma joke supposed to mean?
Let's be honest here, this groups quality is routinely shit, the lack of proofreading is noting new. At this point every new chapter they put out is just another reason why they need to start dropping series so competent groups can pick them up, instead of whoring for donationsThanks for this chapter as always, but the grammar was a bit bad this time, I think it didn't get proofread?
The jokes didn't pass through for the translation and lack of text explaining it.
And the bad grammar simply ruined some, like the turtle-neck thing, I presume the mother mispronounced it in the original text, but didn't in the TL.