Hirple can indeed be pronounced the same way as Purple.
Even though nothing presented here should be considered mandatory, credit should be given where it’s due. Acknowledgment should be given where credit is due.
For example, he tried to “mansplain” something to her, but it was something that she already understood, so there was no point in him doing so. It is appropriate for her to be the one to let his mother know about the hirple phenomenon.