Thanks to @NWSiaCB for translation. I am curious, though, what the original Japanese was that justified the pun on "stiff". Does Japanese have a similar pun on "rigid, unyielding in personality" vs. "erection", or is it a Woolseyism for a different joke?
Have I mentioned this shit is tiny? Because this shit is tiny. 200% zoom just makes the kanji even more blurry.
Anyway, presuming I managed to guess at the kanji the same way as I did last time, it's, "硬い", or "katai". See the Tangorin Japanese dictionary on the characters. It literally does mean "hard" or "stiff", but also can mean "stubborn", which is what Tenryuu means, while Admiral replies back the same word, but meaning its more sexual euphemism.
On a literal level, "何硬いこと言ってんだよ" -> "Nani katai koto itte nda yo" -> "Why did you say such a hard (stubborn) thing?!"
"Slightly Erotic Kancolle" Tenryuu and AdmiralOr rather, don't come into the men's bath.Yo, Admiral!I'm all dirty from playin' with the destroyers.'Cuz the shipgirl's bath is all full of destroyers.Sorry, but lemme use the Admiral's bath facilities. Haanh?
Whazzat?Why're ya creepin' away?"That"?Hahaaan!
So yer scared.*Gulp!**Sigh*Eh?! That much?!Yer unexpectedly chicken, ain'chaa?Yes, it's too scary, so please stay away.Aaaah?
Why ya gotta be such a stiff about it?It's because that will get stiff, you shouldn't come in!