I don't know what sunny means, but I guess in my headcanon I view Michael as a top when he was younger and then a switch/bottom when he is older (Men's ED, stress, age, guilt). Sexuality is complicating and I believe there are gray areas, it's not always so strictly one way or another. I think for him, it's obviously for power over Trevor. Trevor immediately imprinted on Michael because he gave him purpose and accepted him for who he was and all his defects (from Trevor's pov). Trevor was at his lowest: Mother issues, rejected from the Canadian Air Force, etc. and Michael was there to pull him out. I think Michael bit more than he can chew as time went on and a lot more pressure was on him when he had his family on the line. I mean Trevor is not an easy person to be with. He's fucking horrible and crazy.

I think Michael associated sex with power. Him tattooing his name on his bunk's ass in prison is one example. Like why? What is the meaning for that? Is he insinuating he owns that ass? For shits and giggles (possibly)? I think sometimes men are weird. When it comes to trying to act "macho" there is this weird gay implication/joke or effeminizing other men. Frankly I don't get it.
I don't think there was much of an awakening in his younger days, just plain old denial, denial, denial, and emotional repression. It was curiosity and the emotional bond that led to him sleeping with Trevor, but I think he often regretted it after the deed was done, but like a drug he gave in quite often. In my story, this rejection often messed up Trevor's psyche (abandonment issue). I think it was an awakening more after the 9 years between him and Trevor. Those feelings bubbled up again seeing his best friend again, also after his family left his ass he had some time to himself. Guilt ate him up and he took it out on his family and himself and he missed being in the criminal game, and missed sharing that with Trevor. In the game as the story progressed, he did try to make it up to Trevor (possibly out of fear too lol). This is just my view of it, but hell I'm super stoked of what other people think of it.