I think I'm homophobic?! {complete}

I couldn't complain; I had a FBW

      It wasn't long before Steve started to notice that something was off with his best friend. Bucky was acting skittish, spending more time at the gym and less at the apartment. But what really set him off to the problem was when Bucky came home from work extra early one day.
     He had finished there wasn't much to be done at the office, so his super let him leave early. He took an Uber home, energized and hoping to snag Steve to go see the new Wonder Woman movie with him. Unfortunately, the universe seemed to have other plans.
Just as Bucky reached for his keys in his pocket, the door was pulled open from the other side by Steve's latest fuck buddy, Tony- who was an absolute ass, by the way. He had a spoiled childhood and unending daddy issues that blended with a sarcastic wit to create the most obnoxious person Bucky was ever forced to acknowledge.
'Shit.' Bucky thought to himself the next day as he recollected his actions. He opened Reddit to update what he had previously written.
       The other day I came home right when some guy was about to leave, and the guy tried to be polite to me but I ended up being rude to him (don't remember what I said, but it was really obvious I was pissed).
     That was a lie. Bucky remembered exactly what he had said, he just didn't want to admit to the things he had said. Especially the part where he started the altercation by pushing past Tony as he was attempting to greet Bucky and tossing out an unnecessary insult along the lines of 'really lowering your standards these days'.
        After Tony closed the door and left, Steve turned to Bucky.
      "What the fuck. Why are you being such an asshole!?" Steve had practically screamed.
       Bucky honestly didn't have an answer so he said nothing and stared at the floor.
        "Do you have a problem with me sleeping with other guys?" Steve had asked.
      When the guy left, Steve asked me why I was being an asshole. I didn't know what to say, but then he asked if I had a problem with him sleeping with other guys. I said no. For some reason that pissed him off more
    When Bucky had defensively replied "No!" and an emotion that Bucky thought resembled hurt crossed Steve's face for just a moment before he yelled "FINE!" and launched into a rant.
     He said I can't complain since I used to bring my fuckbuddy over and he was forced to see me being affectionate with her sometimes. (I was in an FWB situation with a girl, Natasha, in the early days of me and Steve living together, but I broke it off after a few months and I haven't done anything with anyone since.) I agreed with him and told him I was just having a bad day.
    "Sorry okay! I'm just tired and pissy! Look, man, I don't care who you sleep with, I just want to go watch Netflix and knock out."
     Again, a look of pain swept over Steve for no more than a second. 
    "Whatever. I'm going over to Sam's place. I just need to cool down." He sounded like he was trying to convince himself of that more than tell Bucky his plans for the night, but Bucky didn't point it out.
    He told me he's going to a friend's place to cool off. I said okay. When he was leaving for some reason he casually said, "and you'll be okay if I sleep with him as long as I do at his place and not ours, right?" Or something like that. I told him it's none of my business what he does at someone else's place, but when he said that I felt sick to my stomach and couldn't stop thinking about it.
     Bucky got up and closed his window after posting the story. He decided to take a quick nap before cleaning up for his sister to come over for a movie night. He laid in bed tossing and turning, unable to find a comfortable position. This was going to be a long night.