I had a client ask me to film him and a provider together. It went well. A good time was had by all, and I got some really good footage that he had for his personal use and the provider used for her ONLY FANS. The same client has asked me a couple more times to film him in different fantasy scenarios with other providers. I simply used his camera in his cell phone and then handed over the phone so he had everything and could share with the girls to use the footage as they so desire. I have had experience as a behind the scenes camera girl on porns sets so the request fit my capabilities and everyone was very happy with the footage. I realized that I really enjoy this type of work. I was thinking that perhaps others might be interested? Maybe couples coming to town that want to commemorate their fun sexy time in Vegas. Im looking for something new to add to my offerings at a reasonable price point. I guess what I would be offering more than anything besides the ability to get those unique angles that you just cant get with a selfie stick would be a Vibe. People having sex, especially when it is being filmed might find themselves camera shy. My personality is quite encouraging and sex positive. I think it would be a fun addition to all the ways we like to play together. What are your thoughts? Do I just add this as an option on my regular website where people can see my numerous reviews that Im trustworthy- accountable and professional. Where would I market such an offering?  Thoughts and advice are really appreciated. I'll check back here but feel free to send me an email as well.

There doesn't seem to be any additional expenses associated with it.  So, it seems like all upside.  Go for it.

" . . . . a fun addition to all the ways WE like to play together," are you suggesting there are other services besides massage available that are not listed in your profile?  

There are some ladies who have been reviewed here who offer photo/video of themselves and their client for his use. Usually it's an upcharge, often listed on the website.
If you were to offer the service for others, that might be fun.  If you were to participate that would be a bonus.  Of course you would have to decide if any or how much of a fee for these services.  
I have also found some girls on Tryst looking for guys to record content with them for their OnlyFans page.