I like many of the photographs, but I don't like the ones where you've covered one or both of their faces. People want to see themselves in their portrait photographs.
The photo with the two of them sitting on a bike kissing would be better if you'd moved to the right so you would have seen more of their faces, and the same with the black and white photo. I would like to see a little more of her face. But other than that, I think you did a great job.
I like the bicycle collage...the photo in the lower left corner of it is super-cute. I really do not like the way the lens used in photo 3 renders the out of focus background...I think a lens that renders a more defocused, smoother background bokeh would look better. I think that they will really like the red series. I stopped by your blog...I love that shot of the couple kissing on the overlook by the rail fence--what a beautiful, strong photo that is!
I really like the red collage, the only thing I would change is that picture 3, 4, and 5 are too similar. Do you have a different poses or were you going for a pattern there that I am not seeing? Great job over all though, they look like they were fun to shoot!