Actor Robert Pattinson reportedly called singer Katy Perry "so hot" at the recent after-party for his new movie The Rover in Los Angeles.The Twilight star was spotted flirting with Perry at the after-party before telling his friends that he has a crush on the singer, reports femalefirst.co.uk."They were heavily flirting. At one point, Robert sauntered to the bar with a pal and was heard saying, 'She's so hot,' nodding in Katy's direction," a source was quoted by the New York Post newspaper's Page Six column as saying.Perry had said in the past that she will never date Pattinson and sees him as a buddy. The duo had also sparked romance rumours earlier in April when they spent time together at a music festival. It was reported at that point of time that Pattinson's now-off-now-on girlfriend Kristen Stewart felt threatened by Perry. Pattinson and Stewart ended their relationship last year.