I can't write the direct and explicit scene, and I don't think they are necessary. And really, as a reader I feel like they are 'telling' me something and hoping I will translate that into character feelings and sensations: In your example, shouldn't that movement produce some sort of feeling in him, or in her, or in both of them?
I say forget what is happening with their body parts, what is happening in their heads? What are they feeling? What permanent change is now present, what does it mean for the future?
There is a "why" of how they came to be naked together, so what is satisfied in that final movement of P finally meets V? As Lauren says (+1), skip the genitalia, mechanics, etc. Even if they are not virgins, first sex with a new partner you have known for some time is transformative for both of them, it begins a new chapter in their relationship, and that moment when P meets V is a singular moment because of how it irrevocably changes what they wanted and anticipated doing into what they have done.
The mechanics are not so important. A full sex scene is pretty boring; sex is mostly repeating a motion many times. So I'd avoid writing the 'middle' at all. How they came to the point of intimacy is important, even if you only show him kissing her (or vice versa). Next in importance is the transition out; from completed act to 'normal' (I presume eventually you want your story to continue with fully dressed characters).
Third in importance is the moment actual sex begins (beyond kissing); and what it means to at least one of them. Fourth is any moment of climax. Those are not in order of how they happen, and show what you can skip.
For example, on TV some stories show two fully clothed characters kiss [finally], then fade out, and fade back in with the two characters fully clothed the next day, in the office or court room or whatever. The audience knows they boned, their attitude towards each other shows that too.