TER only allows one review about a doubles session, not two.
How do I pick which person to put the review under

It won't matter, a doubles review won't go on either one of their solo profiles.  Anyone searching for one of the providers included in your double review will find her solo profile and then her double profile with her and her partner.  Just make sure to enter both their websites when you create he review so people can click on both links to view the two ladies.  Not a great system but it is what it is.

You need to create a new profile. Leave the TER ID field blank. Under provider's name, put Joan and Jane then fill the rest out. Like princess stated, include a link to both their ads or websites in your review submission.

If both provider's already have an existing profile of themselves performing together as a couple, not with others, then you can look up their TER ID from their profile and put it in the TER ID field

It's when you try to list 3 or more girls it gets messy. There is only room for 2 so whom do you leave off?

The profile is where you have to make a decision about which provider to use as most of those fields only take one value.

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