The 67-year-old former Olympian - who was previously known as Bruce Jenner - revealed the Aerosmith track became her ''theme song'' when she was struggling with her gender identity and the 69-year-old rocker was pleased to know he'd been able to play a part in giving her comfort.
Caitlyn shared a picture on Instagram of herself and Steven on Tuesday (18.07.17) and wrote: @iamstevent and I are working on our duet for Dude Looks Like a Lady. One of my favorite songs! (sic)''
And she later appeared on 'Jimmy Kimmel Live' to explain the photo.
She said: ''If you noticed today on Instagram, I posted a picture of me and Steven Tyler.
''I was at a fundraiser in Minneapolis, and he was the entertainment. I had met him, I think, once, briefly - many, many years ago. But he was sitting there and I'm thinking, 'I've got to go say hi.'
''So, I go backstage after and I look up at Steven and I said, 'I have had some really, really tough times in my life. For six years, at one point, I stayed in my house, and every once in a while I would get dressed and go sneak out in the dark and drive around. Your song, 'Dude Looks Like a Lady' became my theme song, driving around in my little car with my little CD in there, whipping up the tunes and stuff.
''I said, 'I just want you to know, it made me feel good.' He loved it. He hugged me and said, 'We've got to get together.' ''
Elsewhere on the talk show, the 'I Am Cait' star asked the 49-year-old host to ''spy'' on her daughter Kendall Jenner because Jimmy lives across the street from the supermodel.
She quipped: ''If I brought over some binoculars, could you spy down on her? I never know what's going on in that house.''
Jimmy laughed and replied: ''Can I tell you what's going on in that house? There's a lot of people bringing clothes in and out of the house--just all the time. There's so many clothes going in and out of the house!''
Caitlyn agreed: ''I can see that. No, Kendall is a very great kid.''