Superman goes through an emotional roller-coaster in Action 317 (Oct. 64), and all of it shows on his face.
Superman gets exposed to red kryptonite (wow, that NEVER happens), and it has the effect of making his face colour brightly when he experiences emotional reactions, in this story by Otto Binder and Al Plastino.
Though he spends the day largely as Clark Kent, in the company of Lois Lane, he watches from a distance as his Kandorian friend, the scientist Nor-Kan, sickens, dies, and is buried, all in (apparently) quick succession.
At one point, green with envy, he moves a restaurant called the Green Lantern into a new location, to shine green light on Lois’ face as well. This restaurant will return in the pages of Superman comics in the early 70s. Am I a geek or what?
The effects wear off by the end of the story, and Nor-Kan is buried, with a memorial. Despite this, Nor-Kan appears again in a number of Superman stories in the 70s.
Her boyfriend is Jeff Colby, whom she happily introduces to Dick Malverne and Linda Danvers. Linda had just helped him survive a plane crash, as Supergirl, and when he makes no mention of that, or burying his parachute, she becomes suspicious.
Spying on Jeff, she sees the he is working with organized crime, who operate from a sea base in international waters.
Lex Luthor has also been watching Lena on his own monitor, and is shocked when he sees Jeff Colby.
Supergirl does not want to be honest with Lena, and tell her what she knows of Jeff, so instead she butts in at a dance, and hypnotizes Jeff into falling for her, humiliating Lena in public. Jeff remembers none of what happened, but Lena calls off their engagement.
The Supergirl discovers that Jeff is actually an FBI operative, and was working undercover, infiltrating the organization. Oops! She helps him take them down, and then builds a robot of Jeff and programs it to tell a ridiculous lie, all to cover her own, unfounded actions.
Lena and Jeff marry at the end of the story. We learn that Jeff had arrested Luthor, which seems to be setting up some later story, but doesn’t.
In fact, this is not only the final appearance of Lena Thorul in Supergirl’s run in Action Comics, it’s the one and only appearance of Jeff Colby. When next we see Lena, in Supergirl’s run in Adventure Comics in the early 70s, she is a widow and single mother.