First Look: Loyalties Are Tested On The Big Bang Theory

Penny is put in the middle of an awkward situation between Sheldon and Leonard.

1. Penny is put in the middle of an awkward situation between Sheldon and Leonard.

Everyone is forced to choose sides—and apartments—when a small argument between Leonard and Sheldon escalates into a somewhat heated fight before watching one of their favorite TV shows. Plus, Howard and Raj find themselves squabbling over bragging rights on the next episode of The Big Bang Theory entitled "The Viewing Party Combustion."
Sheldon and Leonard spar in the kitchen.

2. Sheldon and Leonard spar in the kitchen.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Howard and Raj pass the time by playing video games.

3. Howard and Raj pass the time by playing video games.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Amy's controversial opinion surprises Sheldon.

4. Amy's controversial opinion surprises Sheldon.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Howard and Raj disagree in the hallway.

5. Howard and Raj disagree in the hallway.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Leonard stands his ground in front of Howard and Raj.

6. Leonard stands his ground in front of Howard and Raj.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Sheldon and Penny take their large sandwich and storm across the hall.

7. Sheldon and Penny take their large sandwich and storm across the hall.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Howard and Raj are forced to choose sides now.

8. Howard and Raj are forced to choose sides now.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Stuart arrives at Leonard's place in a festive costume.

9. Stuart arrives at Leonard's place in a festive costume.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Stuart then takes his TV-inspired attire over to Penny's apartment.

10. Stuart then takes his TV-inspired attire over to Penny's apartment.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)
Howard cracks a joke in front of Amy and Leonard.

11. Howard cracks a joke in front of Amy and Leonard.

"The Viewing Party Combustion" (Episode 21, Season 9 of The Big Bang Theory)

Watch all-new episodes of The Big Bang Theory on Thursdays at 8/7c.