I agree! I would suggest you also never ever bring them into your home and personal life. From what you described I bet there was some recreational activities going on the side knowing or not.
When on Grinder with 20 yo your dealing with boys that feel they are invincible and immature, heck most of them probably just got pubic hair 4 years ago.
Always separate and treat it like a business arrangement, your the one covering the bills therefore you are the boss, set the rules and enjoy the sex or companionship as you want it.