I can remember the one time when I was about 13, my mom told me I was going to get an enema, not realizing my sister and her boyfriend were in the next room ... they both started laughing which got mom a little angry.
She apologized to me, told my sister's boyfriend to "kindly leave, but you can come back tomorrow because it was time for her enema too." My sister turned beet red ... about the same color I was a few moments before.
When the BF left, mom made us both undress, and gave me an enema as my sister watched me go through my agony.
Then she made me hold the enema while she prepared my sister's enema ... and when my sister was bent over to get hers, I was told I could begin expelling and I was not to get up until all the water was out of my system. It was mom's way of punishing my sister. I think I sat on the toilet for more than 10 minutes while my sister was in total agony.
When I was done, sis got rid of her enema, but mom told me that I would get another one as soon as sister was done.
She complained and all mom said was "You're getting a second one ... you think you can hold it for 15 minutes. If you can't, don't say another word. You'll get yours as soon as Deanna is done."
Now that was a punishment enema she'll never forget ... I think!