Waterproof paint?

When I finished painting and cleaning up at a gig yesterday, a woman (who was also at my last 2 gigs) asked me to face paint at her granddaughter's birthday in June. I agreed, but she mentioned that they're going to have a waterslide and wanted to know if my paint is waterproof. I told her no since it comes off with soap and water and she seems okay with it, but would rather it be waterproof.
I saw in another thread someone mentioned spraying Aqua Net hairspray over the paint, but I really wouldn't feel comfortable doing that on kids haha

So my question is: does anyone know of any waterproof paint? Or am I just going to have to tell her that's not possible?
If not, the kids are just going to have to wait to get painted until after they're done playing in the water I suppose

Temptu has a water proof pallet (must be used with at least 91%alcohol) and colorini is water proof (also used with at least 91% alcohol) but these are not for faces. To be water proof, it would be alcohol based, and not suitable or approved for faces, especially not children. There are airbrush inks that are waterproof too.

Have you thought about getting some colorini and some finger daubers and offering tatoos? These would be on the body but are compatable with pool parties as are glitter tattoos. I have done one pool party where they had face painting. I repainted the kids several times, but they had me there for 3 hours, so it was their money, and they knew what they were getting. The kids kind of enjoyed chosing something new, then swimming and getting another painting. This was the clients residential pool, not sure how a public pool would feel about this. I would make sure if they are renting the waterslide, or going to a facility, that they are good with face paint!

Glitter tattoos are waterproof and are great for pool parties. Once they are completely dry of course!

Face painting just doesn't go with a pool party and you DO NOT want to put tattoo inks on kids faces.

My first design was done by colors from the dollar store( here in Ontario,Canada), much to my surprise they just were taken off with makeup remover cloth. They do not have a large selection of colors, but it could serve you for this purpose.I have a photo but do not know how to put it here.
KAPETAN