In the episode last night--when Benson and Stabler were pretending to be the potential adoptive parents--how do you suppose they got all those pictures of them as if they were a couple throughout the years, to fool the Bulgarian baby broker? The ones showed close up didn't look like they could have been from police social events. They've been partners for at least 10 years, but it doesn't seem like they had much to do with each other outside of work...and they didn't have time (in the context of the episode) to make up a bunch, with Elliot even having a beard in one of them!