Once you're in S1, and you got your arm around her on your sofa,bed,or loveseat, etc.. Lean in smell her neck and lightly run your finger over her lips. If hse takes it in her mouth and sucks it, you're getting head!
If she doesn't then you need to seduce her further, but at very least you'll be making out after the lip touch.
Good Lookin
Skit
__________________
Make a joke, make the date, get off the phone. Period.