Once upon a time, sleepovers at the Henry home were a free-for-all but when a little girl broke her arm... well, it meant Annie changed her tune for Graham's parties. Mike's been running all around town for craft supplies for the ultra-safe sleepover. As Annie accident-proofs the kitchen, Leigh slinks in asking to borrow the car for an Ikea run. Annie's refusal simply means Leigh has to find a more creative way to get to Ikea.
Harris received the Excellence in Journalism award, yet he's celebrating only with a microwavable French bread pizza. Not one to let a party opportunity slip away, Mike suggests throwing him a bash. However, he quickly discovers that their friends carve time from their busy schedules only for "major life events," namely engagements and baby showers. When Leigh catches wind of the rented limo Mike's considering, she encourages Mike to make the celebration happen. A limo means driving to Ikea like the other half.
Ian is excited about the slumber party, but Annie's extremism has him running to Eve for help. Unfortunately, Eve has plans with the oh-so-hot Andrew. Once she witnesses the dragging slumber party, she agrees to distract Annie with random conversation while Ian teaches the kids a violent game.
Ian's new game involves jumping into a padded sleeping bag to be pummeled by whiffle ball bats. Before he can stuff blankets into the sleeping bag, he's ambushed by bloodthirsty eight-year-olds. Annie hears the noises, but stops short when Eve confides she's thinking about having sex this weekend. Realizing her truthful mistake, Eve backtracks but Annie won't let it go. Regardless of what Eve's love interest wants, Annie affirms the final decision is Eve's. After the heart-to-heart, Eve promises the relieved Annie she isn't having sex that weekend.
Desperate to avoid disappointing Harris, Mike tells an itty-bitty white lie - can the guys get together to celebrate Harris' engagement to "Pam?" Of course they can for such a major life event! Only at the restaurant does Mike let Harris in on the secret, but by then Harris is willing to roll with the punches. Meanwhile, Leigh blackmails the limo driver into taking her to Ikea since his limo license is out of date.
The party's actually running smoothly until Harris' friends start revealing their real opinions of him. They were worried he'd never settle down since he was the "love 'em and leave 'em" type. A wife is the best thing that'll ever happen to him. Mike tries to salvage the situation but ends up digging himself into a hole.
Mike profusely apologizes for inventing the engagement, but he believes Harris' life is good as is. After all, he can go home with the cute waitress who's been making eyes at him all evening. When the guys observe Harris chatting it up with the waitres,- Mike insists the waitress' number is for him since he's been cheating on Annie for years. The guys are disgusted and the waitress creeped out. Leigh saves the day, bursting through the door post-Ikea shopping trip and declaring her love for Harris. The first round at the strip club is definitely on Mike.
The next morning, Mike brings Leigh a thank-you-for-saving-me smoothie, but she's in a rush to shut the door... because Harris spent the night to assemble her Ikea furniture.