**If you can get to the point were your fingering her, do it face to face and up close so she is straddling on top of you, but position her ever so slightly raised above you so you have 'air' between her pussy and your crotch. Use your off hand to holder her up and finger her with it from around the waist and then down the back to the bottom so your arm is curled into a C shape almost, if she is wearing nickers make sure they are pulled to the side.

Do this while making out with her, do not make her come from this, almost get her there but dont, then we she is wet as fuck, just withdraw your fingers and lower her onto your erection - which you have subtly unzipped as you have been making out (with your main hand which has been free to do this and roam!) or they have done it themselves to mutually return the favour.

1 of 3 things happen - usually 1:
1) you slip in and start to go at it
2) you start to slip in, she realises whats going on and really hammers it home (incoming fun night)
3) you start to slip in but not fully as she hesitates not wanting to go all the way as she isnt a 'slut', but not pulling back either, you need to meet her half way here grab her by the hips and powerfully thrust home once and hold and gasp like it's the most amazing pussy you have ever been in while holding eye contact. Then in total contrast to the initial thrust, go very very slowly and build up the tempo.

Couple of interesting things here:

1) This is a very very smooth transition from just messing about to fucking all night, by passing all that possible verbal LMR .
2) You are not sticking your dick in her, you are simply positioning it, stopping fingering her and not holding her up anymore. She will be relaxed and naturally lower down, she will feel like it was her choice and she has initiated the sex - since she is moving onto you and you are just remaining still.
3) Ive never ever ever EVER had a girl stop and get off me or offer any kind of resistance, you dont even have to imply your gonna have sex, just say lets make out and mess about nothing more then do this.

** word of caution! Your going bareback here, get a condom on asap try not to get carried away in the moment like she is, have a condom real fucking handy try stop after only a few thrusts and say wait let me strap up first, she will be agreeable to anything now she has committed to it so it shouldnt be too hard as long as she gets to continue. But like I said you wanna be careful here use at your own risk!

Obviously field tested to fuck and back, id only use it on clean girls with limited sexual partners (like we would fucking know) Ive not caught anything from doing this, but that could just be luck, cant stress caution here enough.