Ls my boss straight gay or bisexual?

Recently I've had a conversation with my boss with whom I have a friendly relationship too. I really care about him as my brother because I admire him, he's a great guy with outstanding personality. He's in his middle 20-ties (26 I think) he comes from a very rich family and he's acknowledged as one of the best young architects. The girls find him very attractive, he's tall 1,86 cm blond, dark silver blue eyes, strong jawline and chiseled body
You know, like one of the perfect guys. He's often "molested" by the girls and want to date him. He never had before other type of sexual relationship except the straight ones. And this is what he told me: He said that he'll do ANYTHING to hurt the man who's having conflicts with his family. He drank the whole night at the club to gain the strength, so he decided to seduce his enemy's son (the one who didn't knew that he is his enemy's son and plus the enemy didn't knew that he has other son too beside his adoptive one. Only my boss knew that cause he made some research) He said that "the guy" always looked at him too much friendly and strange like he wants him but never really showed it when there were many people. And he was right about it. The guy confessed his feelings at the club men's room. He was similar like him: handsome guy with great body (working as a vet and model), he had never been with a man before only with girls but he couldn't resist when he saw my boss and that he'll never consider to be in a relationship with man unless with him and he kissed him. My boss unwillingly responded to that kiss. They became a couple but a secret one because my boss wanted that and he convinced the guy that it will be a while and so he agreed. At public they were strangers and at night lovers. They maintained the relationship at my boss house. At first he said to me that it was very hard to him to have sex with "the guy" cause it's a guy. My boss never let to penetrate him in the anus but the guy let my boss to penetrate him. (they had the most intercrural sex,frottage,and oral sex) but with time I saw that my boss started to enjoy in this relationship but don't wanna confess. When I asked him "do you love him?" he said "don't say stupid things, you know why I'm with him..." Yeah, I know that this relationship is just because of avenge but I also know that he fell in love with this guy but he can't admit to himself.
Before you answer this is what you need to know: I'm a guy, his best friend, we are very close and share details about personal life and definitely I'm not in love with him.(I'm straight)

okay well if its not in the open and nobody really knows about it then there is no venge there, I think its a fling I think he could possibly be bisexual or at least bi-curiouse NOO straight guy would ever do this is they hadent atleast thought about being with another man, in that such way , I personally think you should ask your boss , about it , and ask him to be completley honest.

People who paint are called painters. People who commit murder are called murderers. People who engage in homosexual behavior are called homosexuals.

If it looks like a duck, waddles like a duck and quacks like a duck, what is it?

HE IS GAY. He just has to find the courage to admit this to himself and maybe you to.