I am currently working on a certain game's translation. The dialogue goes like this:
Sōsuke: それじゃあ、お互いに愛称で呼び合ってみようよ
Riho: 愛称、素晴らしいですね。では、どのような呼び方をいたしましょう
Sōsuke: えっと、俺のことはダーリンって呼んでみて
Riho: ……やはり破廉恥なことではありませんか
Sōsuke: お、お願いだよ……里穂に呼んでもらいたいんだ、いや、りほに
Riho: それが私の愛称ですか?では……ダーリン
Which I then translated as:
Sōsuke: Then, let's call each other by pet names!
Riho: Pet names? That's wonderful. Well then, what should I call you?
Sōsuke: Uh...call me 'Darling'.
Riho: ....Isn't that too shameful?
Sōsuke: P-Please...? I'd really like Riho to call me that...no, りほに
Riho: Is that my pet name? Well then...darling.
I left the word to be translated as is. Should it be translated as "Rihoni"? Is that how nicknames work? Please feel free to correct my translation attempt. Thanks in advance.