that it feels so good that it is overwhelming her body a little bit. i start to shake before i orgasm. it's normal. sometimes it just feels like too much, though. i might suggest a vibrating ring that you put on your penis (can be used on the outside of a condom). it hits her clit while you are inside. if she is on top she can choose how much the virbrator hits her clit, plus it makes it a little nicer for you (or so my dh has told me), and it can make the penis vibrate a little bit. it's a nice treat. you can buy one at lovers package or i think walmart and rite aid sell them now too. good luck!

I am a man, and sometines I get sexualy excited so much I start shaking. Sometimes it's very obvious. It's normal. And she has to relax completly and to enjoy without thinking of consequences

If she asks you to stop the touching might be too direct, maybe continue but add more lube to your fingers, use a softer touch, or focus your touch on an area around (not on) her clit. It might need a little break. Remember, her clit is WAY more sensitive than your penis.