Panel 1: We see Liz at her computer, e-mailing her friend Dawn. The subject: her taking it slow with Anthony. The funny part is that she has no idea how stupid, pathetic and desperate her blathering about how she guessed they'd been talking up the subject a while sounds.
Panel 2: "We're shopping for a ring tomorrow, I must admit I can't wait to prove I landed a man and am thus not a failure as a woman."
Panel 3: She then extends an open invitation for them to be bridesmaids whenever the fates allow. The fact that the fates will allow it to happen when April planned to be on the farm will, of course, be beyond her control no matter what the little picky-face says. If she gets TOO uppity, she'll just tell Mommy and Daddy about when the Continental showed up.
Panel 4: Her reason: REVENGE! Is it for making her wear a bridesmaid's dress? For having a life? Who knows? Who cares? Alls I know is that Bridezilla-to-be Liz is made of fail.
ETA: Suddenly, Sunday's strip makes a damned sight more sense. She's got a laundry list of people she wants to go "BLEAAHHH!!" to and this is chance to do it.