The episode is called #ItsComplicated if anyone is curious
Basically most of the time Carol is stalking Hal around, but this time she blows him off, he finds out she's dating somebody named Thaal Sinclair, he gets jealous and starts stalking her around so she'll go out with him again, then eventually he begs Carol to take him back and she finally does. Then she admits that she was fake dating Thaal Sinclair to make Hal jealous so he'd pay attention to her again. Then Thaal Sinclair wipes off his flesh-colored disguise to reveal he's Thaal Sinestro, and he was fake dating Carol to get close to Hal so he could get revenge for Hal ditching him and ruining their bromance (I feel I should point out this is also why Sinestro went from a green to a yellow lantern, and they used the word bromance verbatim). Carol and Sinestro start attacking Hal, Dex-starr randomly shows up to piss Jessica off, Jessica tells Hal this is all his fault and he needs to apologize to them. Hal apologizes saying that if he wasn't so cool and handsome Carol wouldn't be so obsessed with him and if he wasn't so awesome and fun to hang out with then Sinestro wouldn't have been so sad when Hal ditched him. Jessica is pretty sure they're about to kill him but instead they forgive him and everybody hugs (Dex-starr says he loves Hal because he tastes like steak sauce). Then they all fly off happily
Jessica is stunned that Hal's non-apology somehow worked.
Long summary but like the episode title says it's complicated. lol