"I like you, you're a Challenge."
Honestly, it might sound sexy in the beginning but sooner or later, when you realise that when your partner, male or female, wins the challenge, they get bored and move to the next challenge. Which I why I Hate it when people treat their potential partners/dates as fucking "Challenges". A little banter and flirting is good but do not fall for the "You're a challenge". That's what these idiots do with "challenges"--get bored and move on, leaving the other one in shatters.
They are people, not trophies that you can attain and then throw it away.