Ryan Reynolds has banned Anna Kendrick from stealing away his wife Blake Lively.

The two actresses appear together in upcoming mystery thriller 'A Simple Favour', and they teased the 41-year-old star as they got flirty on Instagram last month while joking about the possibility of a fling.

Asked about Anna's claims she should be allowed to have an affair with Blake, Ryan quipped to 'Entertainment Tonight': ''I know a lot of guys that would be fine with that but not me, I would like to hang onto her.

''Yeah, please let's not do that... I mean, she'd be well taken care of with Anna though, I think she's got the goods, yeah, but no, access denied.''

His comments came after Blake, 30, shared a poster for the movie on social media, and suggested the co-stars wanted to get closer.

She wrote: ''@annakendrick47 is the hotter, female(r) version of my husband... so, would it reaaaally count as cheating??''

It didn't take long for Anna, 32, to reply, and she suggested it was only fair.

She commented: ''So glad we're finally taking this public... I let Ryan have Deadpool. He can give me this.''

The 'Deadpool 2' star actually responded on Instagram at the time, and appeared to have accepted his fate.

He wrote: ''The most ambitious crossover event in history. I'll miss you both. Tell my story.''

Ryan and Blake have daughters James, three, and Inez, 20 months, together and tied the knot back in 2012.