Sex deals with intimacy
is it possible perhaps that you desire to become more intimate with your partner but just can't and that you become like stone when it comes to expression?
is it possible that your unconscious mind shows a symbol of this in a dream scene featuring a co-worker or maybe someone you view as able to express what you feel?
your subconscious may be telling you it is 'co-working' with you to resolve this if this is the issue.

A.

Sounds like typical male anxiety to me,
being female, maybe I sh/keep my mouth shut.
Being female-HAH- fat chance!
"Fears" of all sorts abound in the bedroom.
In this dream you are a spectator, and remain so
because you are "petrified". Literally that means turned to stone.
Is it your fears that have you petrified?
Or is it your unfeeling heart that makes you believe
your signifacant other will go to someone else?
Also do you feel something is missing in the relationship?
There are too many questions...
Get by yourself and ask the ones that seem most important to you.
Listen to your heart.
Marj