Sexually inappropriate app ads

Where can we report sexually inappropriate ads in apps? I was playing a game with my daughter when an add came up where the object of the game is to undress an NPC. The most offensive part if this is that the NPC looks to be in distress, as if not wanting to be undressed. Obviously, this is gross and rapey and should not be something that comes up as an ad for a game I play with my 8 year old, or anyone.