Kyle Rayner Nipslip
In Hal Jordan & The Green Lantern Corps #24 Soratik Natu learns that Sarko is her son by Kyle Rayner from the future, a fact that Kyle did not share with her. She's so pissed off about it that he brands her future baby daddy with the Sinestro Corp symbol!
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It's not like Kyle hasn't joined the Sinestro Corps before. Kyle collects lantern rings at this point: Kyle goes wide, Hal goes tall, but they could both be argued as the human most in touch with the emotional spectrum.