You say you are going to keep the sexual relations between the two of you? My concern then would be how you are going to keep the site interesting on a week by week basis. What is going to make each week's update different to the previous one? There's only so many positions the same two people can fuck and suck in - plus, adding in other couples / people will give you an exit strategy if you ever decide to pack in the filming but want to keep the site going.
The voyeur idea of watching a real couple doing their naughty business is a good one - but try to base it on any couple rather than specifically you two. Sure, it will be you two at the beginning but you never know what direction the site will go in and you want to keep your options open. If it's called "TerryAndJuneFucking.com" you haven't really got any scope to adjust the content as you go forward, whereas "realitycouples.com" or something like that, could be started off with you two and could then add in other couples as you go forward. Just my
