The Sage must confess that these Seekers http://www.slate.com/id/2245889/ were quite tedious. The Sage must look for new Minions, with better discernment as to what constitutes a Sage-worthy endeavor.
1. The Sage is pleased that you didn't waste your time bothering to consult an expert in child psychology, as these lesser Advisors might merely confuse you. The Sage will helpfully advise you to question this boy about his deviant interest at every opportunity. When he stares at them in the stoer, be certain to loudly call him by his entire anme and say something like, "Homer Eustacious Klein! I've told you you can't have any more latex gloves to play with in your room!" This works especially well if friends, preferably of the opposite gender, of his happen to be in the store. In this way, you will be sure not only to drive this hobby underground, but as an added bonus, he'll want nothing further to do with you once he is old enough to leave home.
2. The Sage will go lightly on you, due to your apparent naivete. Inform your friend that you wish to keep you personal life and your work life completely separated. That is, you will not discuss work outside of work, and will only discuss work while at work. This should ameliorate your need to explain to your friend after hours why you were upset during the day. Once you have done this, begin immediately to seek another position, so that your friend may once more become only a friend.
3. The Sage fails to see any ethical delimma. Your roommate has caused no harm to your pet, and does not use an abusive tone with said pet. As long as the animal is happy, why should its human care exactly what is said to it?
4. The Sage feels that this may be a good opportunity for your friends to get to know one another. Unless you have reason to suspect that some of these people will take an instant dislike to each other, go ahead. Make the event as informal as possible, so that they aren't stuck eating dinner next to and making small talk with strangers all evening. If you could have some sort of icebreaker or other games planned, to pull out if needed, it should lessen any initial awkwardness.