I think as a Boss, you have become too close and overly take care your staffs, besides over pay them and make them feel indispensable, thereby spoiling them and they climb over your head. Move on, let them go, pretty girls are everywhere once you become rich and wealthy they come to you. Usually there 2 to 3 years is a limit and if no married things start to fall apart especially if the pretty girl is too young and insecure and too many boys chasing them.