I didn’t know what to say so I unconsciously hung up the call.
"The phone call, it was Akira-chan, wasn't it…. ….? She is really angry right now, am I right? But it's already too late, onii-san will never be able to leave Nana behind."
As I was withering with terror. Nana-chan quickly sensed it then she began to get her face close to my crotch, and began to lick my balls with that small, kitten-like tongue.
"Uwaaaa! Nana-chan, you shouldn't do that!!!"
"Why not? Akira-chan didn't touch these but she hold the tip inside of her mouth and taste it. But Nana doesn't want to do the same thing so Nana will lick these"
As I expected, the stimulation was as much weaker compared to doing it on my rode, but Nana-chan was liking around to find these shrunken balls of mine, and when she found it, she began to suck it up and drag it out. The sensation of that was so unique that made one spine feel tickled.

Riiiiiiing! Riiiiiiiiing!
Uwwaaaa, another call! This feeling, isn't it Akira-chan again? and something told me that she would keep calling and calling again if I don't pick up the phone.
"Hmm...haaa… onii-san, hurry up and answer the phone. While you're calling, Nana will continue doing this."
It seems like I didn't have any choice so I picked up the phone and...
"Onii-chan, why did you hang up the phone?! As I thought, you went outside with Nana-chan and did some lewd things with her and let her kept all of your sperm, didn't you?… Uuuuu, you promised me, and yet…. I will never forgive you!"
"S...Sorry, Akira-chan! …It’s true that Nana-chan is here, but I haven’t broken my promise yet!!!"
[Only at this time….but if this keeps up, it’s would be….impossible]
As I was calling, Nana-chan became more intense with her actions. The moment she separated her mouth from my ball, she put her palm on the tips of my **** and began to rub it with all her strength.
" Really?! Onii-chan didn’t break his promise, I wonder?"
"It's true...., because...., Akira-chan, do you believe...me?"
Other voices were heard after the other side of the call was silenced for a short amount of time.
" Oji-san, you idiot!!! You promised you would play with Asari only!!"
" Onii-san, if you don't come back home right now.... and continue playing, sleeping, bathing with Nana-chan there then...Even I don't know what I will do to you..."
" … Onii-chan, I was thinking of making a meal for you to eat but…why... why did you go without saying anything? And with Nana-chan...."
It was very chaotic on that side, even on this side---
"*giggle*… No matter what they say, they can’t do anything, right? While they are extremely angry and frustrated, Nana is doing lewd stuff with onii-san right now... Nana has become really naughty”

T/N: if you saw any error I made, feel free to point it out. And again, thank you for reading this bad translation of mine.