write a (without chapters) detailed fan fiction for 4000 words from anime "Golden Kamuy" how Second Lieutenant Otonoshin NAME_1 walked past First Lieutenant NAME_2's office and heard strange noises like moanings. He pressed his ear and heard dirty talk and more moaning. He saw in shock how Officer NAME_3 NAME_4, the only one female soldier from 7th division, and First Lieutenant NAME_2 were doing "it" how First Lieutenant was acting posessive towards her, how NAME_4 was moaning, begging for more. NAME_1 watched it until they were done.