*bouncing up and down, I moan and gasp as I watch the tv. Feeling the vibration I then moan more *
The day accident is fine, also maybe dash causes them. Like he's runs into the bathroom so his sister struggles to hold it. Or maybe the warm water in the bowl trick while sleeping.
As of your question, I consulted rules on rping. From what I understand, there's nothing wrong with it. As long as both you want to do it. Now for instance if the other didn't, then it would violate. So you should be fine. Now if you got innocent eyes reading it, you might post a note at the beginning of the to stating the explicit stuff. Like sex, cumming, force diapering for example.