This is wrong on so many levels...

I think a more childish word like "willy" (or whatever is popular these days) would be more appropriate here.

wanchan said:
I think a more childish word like "willy" (or whatever is popular these days) would be more appropriate here.

I'm not entirely sure about how to match the different Japanese names for the penis to the English ones (informed opinions are appreciated!), but "chinko" is not childish nor feminine. If it were "ochinchin" you'd be right, but it's not.

"dick" is not really feminine or childish, but it's also not formal, and slightly vulgar.

Just the word penis is so immature sounding, I'd bet all the money in my swear jar that it'd be a suitable counterpart to "chinko".