John Krasinski thinks his wife Emily Blunt keeps him on ''track.''

The 38-year-old American actor has been married to British 'Girl on the Train' star for almost eight years and is convinced they work so well because she lets him be himself but will only let him ''spin out'' for so long before she pulls him back on the straight and narrow.

Speaking to Playboy magazine, he said: ''I'm lucky enough to be surrounded by incredible friends and family who keep me on track and don't let me spin out into my own universe for too long - namely, and most important, my wife. I think my wife gets me. Not just to sound adorable, but the truth is she gets me more than anyone else has ever gotten me. And so she allows me to, for lack of a better term, bottom out for a second and get really scared.''

The couple - who have two daughters; Hazel, four and Violet, 18 months together - started dating in 2008 but she banned them both from talking about their careers at first.

He said: ''When we first started dating, that was weird. I was definitely aware of [her fame], probably in a way that could have been extremely unhealthy if it wasn't for how insanely down-to-earth she was. I remember being at my house and saying to her, 'So I just want to have this really honest conversation. I think you're one of the best act...' I didn't even get out 'actress'. She went, 'No, no, no, no!' Very loud. We didn't have that conversation again for a really long time, and it saved our relationship.''

And, although they're very open with one another, John hadn't asked Emily, 35, whether she'd been sexually harassed before she spoke about it recently following the launch of the #metoo campaign.

He said: ''We definitely had the conversation once it blew up to the level that it did. I felt terrible and borderline embarrassed that I hadn't asked her about it. I was like, 'Have you ever had a bad experience?' I think she said in Vanity Fair, like, 'I've had my bum pinched a couple of times, but...'

''First of all, I believe I can't add anything to the conversation. There's so much that has been said and is continuing to be said, and all the things that need to be said are at least out there and on the table now. What we actually piece through and how on to in that conversation, I think, is the most important now.''