Flirting, Fertility and "Free Free Nights." The gang is back and no topic is off-limits in the critically acclaimed fourth season of RULES OF ENGAGEMENT. Married couple Audrey (Megyn Price) and Jeff (Patrick Warburton) relive their "single days" by competing with each other to see who has the raciest past. Meanwhile, fed up with the hassles of planning a big wedding, Adam (Oliver Hudson) and Jennifer (Bianca Kajlich) attempt to race to the alter. And is it possible that eternal bad boy Russell (David Spade) has (gulp) fallen in love...with Timmy's (Adhir Kalyan) fiance?
After Jeff fails to pick up a number of texts from Audrey, she tells him he needs to embrace this new technology. Later, Russell and Jeff are in his office and Russell notices one of Jeff’s female colleagues flirting with him. Russell mentions this to Jeff, who is oblivious, and says it’s harmless and that he should flirt back a little. Jeff didn’t know that harmless flirting was ok, and Russell encourages him to try. However, once Jeff tries it he discovers the woman is actually open to an affair, and Jeff tries to cut it off with a text message. Unfortunately, Jeff still isn’t adept at texting and ends up sending the note to Audrey by accident. Meanwhile, Russell sends Timmy to retrieve his phone from the apartment of one of his one night stands, and Adam struggles with sending out save the date cards for his and Jen's wedding.
When Jeff and Audrey switch sides of the bed, Jeff accidentally tosses over and hits Audrey in the face, landing her in the hospital. Adam makes friends with his noisy Rock Star neighbor. Russell sends Timmy to get him a highly in demand phone and he realizes while waiting in line with other assistants that Russell is the most awful boss of all.
Jeff is looking forward to going to Atlantic City and avoiding Audrey's Aunt Judy's visit. When Chuck calls off his wedding, Jeff (along with Russell and Timmy) goes to Atlantic City anyway. Aunt Judy cancels her trip and Audrey invites Jen for a spa weekend. When they run into Chuck and realize the wedding's off, Audrey decides to get back at Jeff for the deceit. She tells him Aunt Judy deleted his TiVo. But when Jeff gets a call from Aunt Judy, he puts it together and it's "game on". They spend so much time trying to mess with each other, neither really enjoys the gambling/spa they've set out to do. Timmy is good luck at the casino and is used as a human rabbit's foot by Russell and Jeff.
Audrey's upset when Jeff reveals to her that he doesn't believe she saw her dead grandmother's ghost. Russell tries to talk Timmy out of going along with his arranged marriage. Adam and Jen's apartment was broken into. When they discover nothing's been stolen, they decide to buy something of value which would be "worth stealing"… which then gets stolen before they even get it home.
Audrey convinces Jeff to go to couple's therapy, but only after Jeff researches the therapist and learn his "pillars" to a healthy relationship include more sex and leaving your spouse alone after work. The therapy season breaks down, but Jeff and Audrey reconcile after they communicate over their individual frustrations about the fertility process. Russell tries to get over his crush on Timmy's bride to be. Adam tries to take a non gay picture for his engagement photo with Jen.
Audrey lies to her unattractive friend Liz that Jeff is attracted to her. Audrey misses a dinner she plans with Jeff and Liz, leaving them alone together. Liz asks questions of why Jeff finds her attractive and causes Jeff to drink her strawberry daiquiri, which gives him an allergic reaction that puts him in the hospital. Jennifer is convinced that she needs to lose weight for her wedding dress.
Competitive tension flares when it is revealed that Jeff used to date the star of Jennifer’s favorite dancing competition show. Russell is depressed by the fact that his assistant, Timmy, is marrying the girl of his dreams, Suneetha. Russell pounces on Timmy’s hesitations about getting married and encourages him to dump her. Timmy finally breaks it off with Suneetha but tells Russell that Suneetha plans on returning to Mumbai. Russell rushes to stop Suneetha and tell her how he feels. He shares his feelings with Suneetha and she lets him know that the feelings are mutual however she must return to India. The two share an intimate moment before Suneetha drives off, leaving Russell feeling content.
Timmy finally loses it with Russell who is perplexed. Russell claims it's his "tough love" approach and brings Timmy to a video game launch party hosted by his former assistant, Maynard, to prove how powerful his approach can be. Unbeknownst to Russell, and much to Timmy's amusement, it seems that Russell was the muse for Maynard's video game "Vanquish the Gnome." Jeff is upset that he has lost his "free" free night as Audrey's last single girlfriend has moved away, so he encourages Jen to invite Audrey to go out with them. The plan backfires when Audrey invites Jen and her friends over to the apartment. Jeff reluctantly goes with Adam to the video game launch party. But instead of enjoying the party, Jeff makes his way up to Maynard's hotel room and spends the night enjoying room service and his hi-def TV.
Jeff inadvertently sticks himself with Audrey's estrogen shot. He goes with Audrey to a work event but spends most of the night concerned about not hearing the score of the Ranger game. In the end, Audrey's boss tells Jeff the details of the Ranger's win, but to Audrey's surprise, Jeff stays on his best behavior. They both wonder if maybe it's the estrogen. Russell invites Timmy to be his guest at the Rangers game. Timmy shows up wearing a Bruins jersey and turns into a fierce rival, taunting fans and causing Russell great discomfort. Adam takes Jen to the game for her birthday with Jeff's tickets. He spends the entire game playing video games and eating hot dogs with a 12 year-old in the seat next to them.
Jeff (Patrick Warburton) and Audrey (Megyn Price) are not having luck with their pregnancy, so they decide to investigate finding a surrogate (Jaime Pressly) to help them. They want her, but she's deciding between the Binghams and another family. Hilarity ensues as they want to convince her to be THEIR surrogate.
Audrey (Megyn Price) attends her high school reunion in Nebraska with Jeff (Patrick Warburton) in hopes to show her classmates she is no longer a loser and has made it in the big city. Not one to spend time alone, Russell (David Spade) crashes Timmy's (Adhir Kalyan) dinner party, bumping into invited guests Jennifer (Bianca Kajlich) and Adam (Oliver Hudson).
Audrey (Megyn Price) is accused of sexual harassment at work by a new young, attractive mailroom employee. Jennifer (Bianca Kajlich) and Adam (Oliver Hudson) disagree as she refuses to believe a woman can't get a simple backrub from the man she loves. Russell (David Spade) is stuck in the middle of a competition, after Timmy (Adhir Kalyan) challenges Jeff (Patrick Warburton) to a game of cricket.
Spontaneously, Adam (Oliver Hudson) and Jennifer (Bianca Kajlich) decide to go to City Hall to get married, and invite Jeff (Patrick Warburton) and Audrey (Megyn Price) as their witnesses. In efforts to keep the wedding a secret from Timmy (Adhir Kalyan) and Russell (David Spade), Adam lies and great confusion arises.