偷看一眼 sounds like "Ta kan yi yan": wrong lyrics (as happened with 一切都这么美好 which is sung as 一切都变得美好) or weird pronunciation?
Trying to make sense of a tweet-length song is hard, but since the song is from a romance movie in 1980, it could be a boy meeting a girl for the first time. 


His first glance warmed her and brightened her world. 
His second glance established the fond love and sealed her fate. 


That is all I can think of.