Brand New Former Vanilla Needing Help

[BeardOfGlory]

I was recently introduced into this world by my girlfriend, who is a very active submissive. I am very open and acceptive and would like to pursue the role of a dominant.
She has been trying to find a new compatible play partner for quite some time. Last week I went with her to meet a dom she has known for a few years from local conventions. Very professional, sensible man. Asked all necessary questions and provided us with great answers when asked. Was even very excited to take me on as a mentee.
Two days ago I accompanied her and observed their first session together. Coming from a completely conservative, vanilla point of view, it was completely unnerving. Seeing the woman I love being beaten (a felony in the normal world) by a compete stranger as he feels her butt and smiles as he performs breastplay, made me see red.
I know jealousy is natural (any sane human would feel the same) and he assured me he gets no arousal (sees himself more of a composer). But I do not like seeing her in pain, and seeing her with almost tears in her eyes hurt me. What can I do to control my jealousy and keep my mind at ease?

TLDR; How do you rationalize a submissive lover having a play partner and how do you subdue the natural jealousy?

 

[Sharp Shooter]

As bizarre as it appears, the activities experienced by your g/f trigger a huge endorphin release. This can also be a great stress reliever, something to consider if it's around school finals, etc.

Don't take D/s to be so much sexual as it's primarily mental/emotional. Try to understand the motivation, what she gets out of it and more importantly, why she wants this. Once you understand, you won't be competing against ghosts.