I've done this a few times as a Dom for a sub couple, either with me remote and them together, or all three of us remote from each other. It can be really fun.
The cool part is that you have a lot more options. With pure online, there's always a trust factor, and of course the distance factor. With a couple, they know each other, so pics between them are usually ok from the start, and if they're together they can do bondage on each other, etc.
10/10 would recommend.
