After John and Carrie have sex for the first time, we see that John has a tattoo on his right arm and nothing on his left arm. During their second date, in one scene when John climbs on Carrie, his tattoo is shifted to his left arm. The next scene sees that the tattoo is back tohis right arm again.
In this episode, Miranda dates "the angry guy" and his name is Kevin. Fast forward to Season 3 episode 6 where she gets chlamydia and has to call all her past boyfriends to tell them. She calls him and he picks up and quotes his name as David.