Tropical Island Maniacs: My Host Family is so Lewd! 4

After holding back for a week, Akari and Tsuzumi reward Kei with a swim at the beach, where they of course have more then just swimming planned. Once they get back from a day full of threesomes and creampies, Kei helps their mother, Tamaki, move some boxes... as well as control her libido. Will Kei be able to hide his secret relationship with their mother from Akari and Tsuzumi?