Episode is rated for ages 13+, and can be displayed in apps of the same age rating. Ads for Episode are controlled by the ad provider. Episode does not have any control regarding which apps are displaying ads for Episode.
Please check the age rating of the app which has shown Episode ads. If the age rating of the app is below the required 13+ age rating, please contact that app's support team to file a complaint. They will be able to forward your concern to their ad provider to have the advertisement removed from display.