In before commentary... I'm guessing he is liking how she is filling out in preparation.

The_Shadow said:
In before commentary... I'm guessing he is liking how she is filling out in preparation.

That's pretty much it. Here's title/commentary from pixiv:
==========

K: "They've gotten quite a bit bigger, huh?"

R: "Wh-Where do you think you're groping? Honestly... having a pervert as the father is going to make this a lot of work. Of course, they've also grown a little- ...! Well, sorry for being flat!"

Artist Commentary

07/29/2012 00:15 793×751 SAI
「ずいぶん大きくなったね。」
「どっ、どこを触って言っているのかしら？　まったく・・・スケベなお父さんで先が思いやられるわね。　確かにソコも大きく・・・って、小さくて悪かったわねっ！」