Did you say his colleague was passed out on his bed for the meeting? Play safe and no one should be there at all.
I have met guys who I thought they were gay, not bi. Just enjoy the session and no matter what, you are doing him service... he may be gay or exploring, or he might just be an open man, maybe metrosexual. I truly believe in just enjoying. Don't think hard and just go in the moment.
One of my favs I swear has to be gay. Yet we have so much fun and I feel so comfortable. Maybe I should tell him I want to watch if he does.... the dirty with a hot guy? lol