As a boss, if I've called somebody into my office to have a talk about attitude or productivity issues, I would have already spoken to my boss as well as HR before calling you in to let them know that there is a potential issue. Both would have told me to begin documenting and to keep them informed. If I was you, I would expect another meeting in the future, probably more formalized if the situation, in your bosses mind, hasn't changed for the better. If you're in the union, I would check your contract as to whether your union rep is able to be present. If you start wailing about getting a lawyer, the discussion will end and now you will be dealing solely with HR... who will be checking everything with the companies legal counsel.
My obligation to telling my team that I won't be in is solely who should they contact regarding attendance issues (e.g. please call X if you will be out sick in my absence, etc.), when I will return and if I will have access to my e-mail or voice mail while out. If they ask me where I'm going or who I'm going with, I'm not hiding anything. I'll tell them. Otherwise, they don't need to know.. My folks tell me they're going on vacation and I just tell them to rest up and have a good time. If they offer more info, we can chat. If they don't, I really doesn't matter to me.
As a boss, whether my staff like me or not is totally irrelevant. Whether I personally like them or not is irrelevant. We're here to do a job for which we get financially compensated. I respect my folks and expect the same in return. My credo is "Don't make me look bad, don't make more work for me and do your job" That's it. Putting out fires and babysitting should be a very small part of my job. If someone is making me do that more than necessary because they're causing unwarranted drama, I don't need them.
In terms of someone being 'the best worker'... meh. I'll take someone who is a team player over the hardest worker any day. Peoples concepts of what makes them 'the best worker' is often times delusional.
Going to HR about the boss... you can try that. Have you been documenting yourself whatever issues real or imagined have been going on? Your boss probably has if he's any good. Unless you were humiliated in front your colleagues, physically threatened or sexually harassed, HR is going to look at this as a personality conflict. Worst case scenario, you'll be told as professionally has humanly possible to deal with it or find another job. Best case scenario (you think) would be you are moved to another department with a different boss. From what I've heard from people who have had this happen, you may find yourself out of the frying pan and into the fire. The new boss is going to resent having a new person foisted on them and odds are, your reputation has followed you. It may work out well, or this new persons managing style may be insufferable. Personally, I'm not a clock-watcher. I don't freak out if people come in a little late or duck out a few minutes early. Some of my other colleagues in supervision are really tough on that.
Still not sure what your boss being gay or bitchy has to do with anything. Sounds like you're jealous or have a crush. The '26 years old' and 'Dominican boyfriend' facts seem to point that direction. Is he treating you just like the other folks and you feel you deserve special treatment because you and he are both gay? Because if he did do that, he could be fired or at the minimum reprimanded for showing preferential treatment. I could scroll up and read all the posts for more info but I'm feeling lazy and my DayQuil is kicking in. Also I can't tell from subsequent posts which are from OP and which are from others pretending to be him.