The 32-year-old singer recently claimed the 'Slow Hands' hitmaker is always trying to flirt with her, despite Katy insisting she isn't interested in pursuing a relationship because of the nine-year age gap between them.
She said: ''I see him around all the time, he's always trying to like get my number to like maybe flirt with me but I'm like 'I could babysit you I'm like your mum!''
Now, the One Direction hunk, 23, has given his own side of the story and urged the 'Bon Appetite' singer to ''stop being mean'', claiming he simply wants to be friends with the beauty.
Speaking to the camera during an appearance on Australian television show 'The Project', Niall joked: ''Katy, please stop being mean to me! She is just finding any excuse to just patronise me and go around spreading rumours about me. I just want to be her friend.''
Katy could well be Niall's type though, as the star - who previously romanced the likes of Ellie Goulding and Selena Gomez - previously claimed he liked girls with dark hair, although he insisted he isn't looking for a relationship right now.
He said: ''I think I got a type, anyway. Dark hair, dark eyes. Someone I can see as a friend. At the moment, I'm enjoying being 23. I only get one go at me 20s. I'd like to give it me best go. I'm happy to go home alone on a Saturday night, drink and watch football.''
Meanwhile, the 'This Town' hitmaker has said he's in no hurry to settle down with anyone as he's ''flat out busy'' with his solo career and doesn't think a relationship will ''fit in'' with his hectic schedule.
When asked about his love life, he said recently: ''I've been flat-out busy and kind of went through a stage of not caring about it for a while and I'm going to be busy now for the summer again.
''So I don't really know where I'm going to fit that part in. But if it happens, it happens. I've got many years ahead for that.''
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