Postscript: Romaji by Mink; color-coding by Mierna; translation by arcobaleno.
Note: "Ue ue" isn't just a sound effect in this case, but the song's constantly been described as being age-age (上げ上げ) = hyper, but the girls joke around that instead of reading the kanji as "age," the song goes with the "ue" reading.

（ちまただでうわさの　SEXY　うえうえ）
（ちまただでうわさの　SEXY　うえうえ）

ほしいなら　すべてをあげるけど
（SEXY　うえうえ）
心まで　奪えるもの？

ずるいこと　いっぱいする人ね
（SEXY　うえうえ）
自然なら　なお悪よね
（ちまただでうわさの　SEXY　うえうえ）

水しぶき　上げながら　あぁぁ
（SEXY　うえうえ）
優しさを　連れてきた　SEXY BOY
（SEXY　うえうえ）
未来まで　続くなら　あぁぁ
（SEXY　うえうえ）
愛に任せ　Fall in Love

イッパイ期待
イッパイ期待
そよ風に寄り添って
（ちまただでうわさの　SEXY BOY）

(Chimata de uwasa no SEXY ue ue)
(Chimata de uwasa no SEXY ue ue)

Hoshii nara [Wa/Ka] subete wo ageru kedo
(SEXY ue ue)
Kokoro made [Mu/Ka] ubaeru mono?

Zurui koto [Wa/Ak] ippai suru hito ne
(SEXY ue ue)
Shizen nara [Mu/Ak] nao waru yo ne
(Chimata de uwasa no SEXY ue ue)

Mizushibuki agenagara [Wa/Ka] aaa
(SEXY ue ue)
Yasashisa wo tsurete kita [Wa/Mu] SEXY BOY
(SEXY ue ue)
Mirai made tsuzuku nara [Ka/Ak] aaa
(SEXY ue ue)
Ai ni makase
Fall in Love

[Wa/Mu] IPPAI kitai
[Ka/Ak] IPPAI kitai
Soyokaze ni yorisotte
(Chimata de uwasa no SEXY BOY)

(That rumored sexiness, ue ue)
(That rumored sexiness, ue ue)
 
If you want it, I can give you everything
(Sexy, ue ue)
But to the extent of stealing my heart?
 
You're a person full of sly tricks, aren't you
(Sexy, ue ue)
If it's natural, that makes you even more wicked
(That rumored sexiness, ue ue)
 
Ah, while you were splashing in the water
(Sexy, ue ue)
You led me along with kindness, sexy boy
(Sexy, ue ue)
Ah, if this goes on to the future
(Sexy, ue ue)
Leave it to love and fall in love
 
We've got big hopes
We've got big hopes
Nestled by the breeze
(That rumored sexy boy)