I remember Nomi started behaving very weirdly when Emma came, as if she was jealous that there was a new girl in class, I also think Emma recognized it very early on and started trolling Nomi about it.
There are more than a handful of episodes where Emma and Sam would accidentally show up wearing the same damn outfit, Nomi would make passive aggressive comments about this and then something very odd started to happen, Nomi started to gradually lighten her hair and style it similarly to Emma's hair.
Whole thing was very catty and sexually charged. Sam could have had them doing threesomes on an air mattress floating in the Gowanus Canal if he wanted to.