That's when you're supposed to say "no, daddy, please stop, not again..." while crying.
Otherwise, "stop that, or you'll give me an erection" also works.

To be honest I'm quiet frankly surprised more of this Artist's works aren't on here. They've done a LOT of stuff both on Pixiv and Twitter. Fingers crossed to see if at least some of these get approved.

edit: Well Its clear this one won't get approved. I'll just make note of its looks and the looks of those that get approved to guide future uploads