So, she tried. she tried very hard. And was being succesful until Seth confronted her about it.
In a way, she wanted him to feel she was distancing herself from him. She wanted him to ask her about it. She wanted to tell him why. After seeing the episode in which Jim confessed his love for Pam in ‘The Office’ that was all she ever dreamed doing.
Having this inside her…these feelings. It was unbearable.

“HEY GUYS !” Niki screamed, stepping between them. “what are you guys still doing here?!”
“uuh…we were in the Foreign Language Club.” Seth said looking straight into Shae’s eyes.
“yeah. and we were having a real important conversation..just..now.” Shae said looking at Niki harshly. But Niki was so oblivious to anything not related to her, she missed Shae’s indirect GO AWAY ! message.
“OH! Seth, I’ve been meaning to ask you ALL day. can you give me a ride home?! pleaaase” Niki grabbed Seth’s arm and brushed up her chest against it. Seth did not have feelings for Niki anymore… but he was a guy.