User blog comment:SeddieKissiOMG/Possible reasons why it could've been Melanie in iOMG/@comment-3354907-20110416025021

It wouldn't make sense for the girl in to be Melanie:

1. Why would Melanie even be at Ridgeway in the first place? The lockdown is for people who go to that school only

2. Sam has a distinct clothing style that's much more different than Melanie's. Their voices sound different too (Melanie's is higher pitched)

3. Sam seemed very awkward after kissing Freddie for the first time, wheras Melanie wanted to kiss hims more. The girl in this episode seemed awkward as well 4. In the last scence, Sam gave Freddie her "double fist face dance threat" - something that Melanie would never have done

5. Carly wouldn't have been as shocked (if she was in on the act, I mean)

6. Dan most likely would've said something if it was really her twin

7. A LOT of fans would be angry if they found out the girl was really Melanie

8. ALL of the promos mentioned Sam, Sam, and only Sam

Also, commenting on your last point, I am a Seddie fan and I was VERY excited after this episode came out! I'm pretty sure a lot of other Seddie fans were excited as well.