Khloe Kardashian Smiles, Wears Wedding Ring at Katy Perry's Labor Day Party: Picture

Khloe Kardashian flashed her wedding ring and kept a smile on her face while hanging out with friends at Katy Perry's Labor Day house party on Monday, Sept. 2. Credit: AKM-GSI

California girls unite! Khloe Kardashian found solace with surprise pal Katy Perry at the "Roar" singer's Labor Day party at her Hollywood home on Monday, Sept. 2, after a trying weekend following husband Lamar Odom's DUI arrest.

The reality star, 29, was all smiles as she chatted with friends and posed for photos that she posted to her Instagram account that night. The Keeping Up With the Kardashians star kept her look simple in jean cut-offs and a black V-neck T-shirt, with a flannel shirt tied around her waist.

One noticeably flashy addition to her otherwise casual outfit? Her gleaming 12.5-carat wedding ring. The reality star, who tied the knot with Odom in 2009, has been photographed both with and without the bauble in previous weeks.

One day earlier, Kardashian took to Twitter to tweet cryptically about her shaky marriage, telling fans, "As much as I wish I were made of steel … I'm not."

Odom's wife of four years also previously tweeted several glamorous selfies of herself, as well as the message, "Smile … no one will notice."

"Khloe did keep her marriage issues with Lamar a secret from her family for quite some time -- no one knew," a source previously told Us Weekly. Added another insider, "Khloe has seemed very unhappy lately. She's not herself. It's heartbreaking to see how unhappy she is, because she is in love with him. It's so sad."

On Friday, Aug. 30, Odom was arrested for a DUI after driving too slowly on the 101 Freeway in the San Fernando Valley. After failing the standard alcohol test, the athlete then refused to take a chemical test -- leading to a one-year license suspension.

"The problem is cocaine," a source told Us of Odom's struggles with substance abuse. "He would be high for three or four days at a time. …The addiction had taken over their marriage."