Huh. I thought that was "canoodling". I need a better dictionary.

Well, it is a bit more classy than "Hey, want to f*ck?"

I'm convinced there is no right way to ask that question. It's kind of a form of roulette (maybe Russian roulette with 5 chambers loaded), and depends upon a variety of factors. Obviously, the individual and their frame of mind matters, but frame of mind can vary based upon all sorts of things. Fatigue. Blood alcohol levels. Libido. Level of arousal. Tone with which the question is asked. General sluttiness of their character. (And that is not necessarily an insult. I like a little bit of sluttiness in some people.) Past history with that person. How attracted that person is to you already ... if they wanted you to ask, you'll have more leeway, or at least they'll be more forgiving.

Columnist Franklin P. Adams (1881-1960) and Algonquin Round Table member once humorously explained how things tend to go when a man takes his date home at night and they're at her front door. (There are four short scenarios.)

https://books.google.com/books?id=nmaCDwAAQBAJ&pg=PT27&lpg=PT27&dq=%22he+wants+to+come+in+and+she+doesn%27t%22&source=bl&ots=CKvy7E8Rdu&sig=ACfU3U2xs1t9VAn5aUb6ww7zkeKKH0tP5A&hl=en&sa=X&ved=2ahUKEwioxeS7g6P0AhWDVTABHfwHA-IQ6AF6BAgEEAM#v=onepage&q=%22he%20wants%20to%20come%20in%20and%20she%20doesn't%22&f=false