Flip her over first

Being so close to orgasm for so long has boiled your brain. You growl and roll Jan over, keeping yourself impaled inside her. You land on top, and she grunts. You are wild with unsatisfied lust and begin to thrust hard and fast into her. She squeals with pleasure and gasps. You lean lower and suck hard on one of her nipples, which brings a loud wordless shout from her throat. Her nails dig into the flesh of your back; the pain just makes you more frenzied. You bite a little hard on her nipple, and she screams, scratching down your back. Her body bucks beneath you, and somewhere in the back of your brain you know she's cumming, but you just pound into her until you finally erupt, growling loud over her head. Your body convulses as it releases its payload into Jan's writhing form. The two of you melt into a single orgasmic entity, noisy and ecstatic.

After an eternity, your strength fails, and you collapse on her still-squirming body. Her cries turn to pants as she settles down from her pleasure peak. You can feel her pussy muscles tighten and release several times in your sex-satisfied stupor -- mini-orgasms.

She caresses your back, which sends both the pleasant sensations of her touch, as well as the sharp, also pleasant, pain when she hits your scratches. After many minutes of just breathing, you finally have the ability to speak again.