Ep 5. The Hot Tub Contamination

In The Big Bang Theory season 10 episode 5, titled "The Hot Tub Contamination," Sheldon is excited to celebrate his birthday, but things quickly take an unexpected turn when he learns that Amy is hosting a brunch at her apartment the same day. He initially tries to convince her to cancel the brunch, but when that doesn't work, he decides to combine the two festivities into one big bash.

Meanwhile, Howard and Bernadette have purchased a beautiful new hot tub, which they invite their friends to come and enjoy. However, when Stuart accidentally shows up with a cold sore, the group becomes paranoid about the hot tub being contaminated with herpes. They scramble to find a solution, resulting in several hilarious mishaps.

As the party continues, tensions rise between Sheldon and Amy as they compete for the attention of their friends and try to one-up each other. Things come to a head when Sheldon accidentally drops Amy's prized tiara into the hot tub, causing her to storm out in a fit of rage.

The rest of the group tries to salvage the party, but when Raj accidentally spills red wine all over the white sofa, chaos ensues. Despite the many setbacks and mishaps, everyone eventually comes together to celebrate Sheldon's birthday and have a good time.

"The Hot Tub Contamination" is a classic Big Bang Theory episode that showcases the show's trademark humor and witty writing. With plenty of laughs and unexpected twists and turns, it's a must-see for fans of the series.