"@annakendrick47 is the hotter, female(r) version of my husband... so, would it reaaaally count as cheating?? 🔪👗🍸🎀🖤," Lively jokingly wrote alongside the image. The caption (obviously) caught the Deadpool 2 star's attention and he sarcastically replied: "The most ambitious crossover event in history. I'll miss you both. Tell my story."
But that wasn't all, Kendrick also chimed in with her own witty response.
"So glad we’re finally taking this public. I let Ryan have Deadpool, he can give me this," the actress jotted down.
In May, Lively mysteriously deleted all her photos and videos from her Instagram and returned a couple days later to debut the A Simple Favor trailer.
The Paul Feig-directed film centers around Stephanie (Kendrick), a mommy vlogger who seeks to uncover the truth behind her best friend Emily's (Lively) sudden disappearance from their small town.
Check out the trailer in the video below.
A Simple Favor hits theaters Sept. 14.