What does いいんかい mean here?


[![enter image description
here](https://i.stack.imgur.com/PZmEq.png)](https://i.stack.imgur.com/PZmEq.png)

So the kid says he only got a present for his grandfather and not his mom
after coming back from the trip and that he wants to see his grandpa's happy
face.

I'm stumbled on the exchange after. From context it seems akin too

"What about mom?" and "It's not good but I forgot" is what I get from context,
but I'm not really sure.




Your guess was good, it roughly means "What about mom?". The mother's "いいんかい"
is not exactly an honest question like others have suggested.

〜んかい with the right intonation, which you can't hear on manga pages
unfortunately, is used to add sarcasm to the expression before it. So
お母さんはいいんかい _literally_ means "Are you okay not giving one to me?", but if you
account for the sarcasm, it becomes "And your mom's just fine?" (="You only
thought of grandpa?"). She's more reproaching him than actually asking a
question, though she's not angry, as you can see by her facial expression.

〜んかい probably makes more sense when you hear it in the wild:
[https://www.youtube.com/watch?v=2gRe4sLbpFw&t=742s](https://www.youtube.com/watch?v=2gRe4sLbpFw&t=742s)

Transcript:

[code]

    おお〜
    ３５！ (="35 stacks [of the dodging buff on my character]!")
    *enemy hits him anyway*
    当たるんかい！ (="Aaand he hits me.")
    
[/code]

As you can hear, the person isn't mad; it's something more like sarcastically
expressed surprise. The dodge chance in the game was only 35%, but the
discrepancy between the speaker's surprise at reaching 35 and then getting hit
anyway is what makes it funny. As a side-note, as others have said, the
expression indeed comes from いいのかい/当たるのかい. Contracting the の to an ん is done
intentionally in these cases to make it sound funnier. There _are_ instances
where いいのかい/いいんかい is a real question, but the intonation is different and not
as flat -- and in the manga, the context would be different (the missing
question mark and the sweat drop on the mom's face provide a hint, but it's
hard to read without listening experience).




いいんかい is いいのかい with a slight dialect. This is a meaning of いい that might be
counterintuitive - if you're asked if you want a bag at a shop, saying いいです
means 'no thank you'. It's a little hard to translate simply in English here
but the sentence overall means 'So I don't need one?' or 'So you're fine not
giving one to me?'

Japanese often repeats the verb to answer a question. So よくない here in context
just means 'no'. 'No, but I forg- I was a little busy...'

