The 'Gravity' hitmaker had a three-year on/off relationship with the 'Teenage Dream' singer until 2015, and when she was recently asked to compare her bedroom antics with John, producer Diplo and her most recent ex-boyfriend, actor Orlando Bloom, the 32-year-old pop star opted for the singer/songwriter.
However, when asked about his former partner's comments, John had little to say in response.
He told Rolling Stone magazine: ''I don't have a cool enough thought for you.
''I've hacked this game. I pay very little of the price of fame now. I get to play the music that moves me the most.
''I'm having the time of my life. I'm 39 - I remember 32. I don't wanna do it again.''
While Orlando hasn't commented on his ranking, Diplo - who briefly dated Katy in 2014 - recently joked he didn't even remember making love to the 'Swish Swish' singer.
He quipped: ''I don't even remember having sex. I won the bronze medal in sex Olympics.''
While John played coy about Katy's comments, he has previously been more forthcoming about his sexual exploits and famously described former girlfriend Jessica Simpson as ''sexual napalm''.
Dubbing the blonde beauty - who he dated from 2006 to 2007 - ''a drug'', he said in 2010: ''And drugs aren't good for you if you do lots of them. Yeah, that girl is like crack cocaine to me.
''Sexually it was crazy. That's all I'll say.
''It was like napalm, sexual napalm. Did you ever say, 'I want to quit my life and just f***in' snort you? If you charged me $10,000 to f**k you, I would start selling all my s**t just to keep f***ing you.' ''
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