I like the fact that this item didn't rush to talk the reader through the characters' plans. The story was about planning to carry out a crime, and I think you did a great job playing that out. Justin and Liam were compelling characters who kept the story engaging and interesting.

I thought the characters of Sebastian and Lacey could have been better developed. It's never really explained what Sebastian did to warrant his classmates plotting his death (other than "snitching" on them ditching class, which seems like an excessive amount of retribution for a pretty name initial offense), nor is it really detailed why Lacey would agree to a date and sleeping with Sebastian. Some additional context would help develop these characters a little more and help the reader get a sense of the underlying motivations here. Even if the intent is to portray Justin and Liam as sociopaths who kill people for no real reason, it would be helpful to have that more clearly established by the end of the story.

Overall, I enjoyed the story and think it has a lot of potential. Once the supporting characters are ironed out a little and the plot developed a tad more, this can really be an incredible flash fiction story. Nice start!