How many times do we have to say its not about what you say its about how you say it. These type of questions are so stupid because it presupposes that there are some universal lines that will just have girls jumping on you. Its the same thing as using pick up lines, humans are more complicated then that, its not some input output function. There is no combination of words that guys use on girls to increase the flirting levels, no secret password to get them to off pant, no enchantments that will raise the pheromone levels up. Ultimately you cant force something that isnt there.

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Physical escalation making her feel comfortable around you and mutual attraction is what will lead to where you want it to. The advice about talking about sex for example will only work if she doesnt find you a fucking creep. So continue working on yourself, being confident in yourself, that is way more conducive than looking for the magic lines that will "turn a conversation sexual".