bradleeM: Orco

What do you think made you get an erection? Has that ever happened to you before? From what I understand if a person is totally str8 there is no way seeing another guy naked is going to give one a hard on. Could it have been something else that triggered that reaction? Have you had a mutual jerk off with one of your friends before this incident? Maybe your seeing the long cock being fingered reminded you of a previous jerk off with a friend. Have you watched porn before? If you have done that and jerked off to porn then maybe seeing the dude finger himself reminded you of that.

Why did you leave? Because of your erection?

I would not worry about it too much. When you return to the sauna see what your reaction is to a guy with a smaller package. If you get another erection then you are probably bi. Whatever you do enjoy yourself , safely.