The "SexyBack" hitmaker faced criticism last month when he was photographed looking cosy with his "Palmer" co-star during a night out in New Orleans, Louisiana.
In the images, Timberlake was seen holding Wainwright's hand, while she had put her hand on the married singer/actor's knee.
The pop star subsequently issued a statement online expressing regret at his "strong lapse in judgement," although he insisted "nothing happened" as he shared his sorrow for putting his "amazing wife" through "such an embarrassing situation."
Now it appears Timberlake is trying to smooth over any tensions with Biel by publicly showing her love on Instagram as she promotes her partnership with yoga brand Gaiam in a pair of posts.
Alongside a video clip of Biel posing for photos with her "team," he wrote, "Squad!" and added a heart-eye emoji, while he also left the same image and two red hearts in the comments section for another clip about Gaiam products.
Timberlake and Biel wed in 2012 and are parents to four-year-old son Silas.