There are many signs when a girl reach orgasm. The easiest to identify is their body. If she reach orgasm in 5 min., I presume she must have intense body cram. Next time keep an eye on her and see if she stretches her body one side or the other. Then see if she'll grab anything tight. Again, this is assuming her body reaction is very sensitive. Another place that you can't see is inside her vagina. The vagina will "squeeze" anything in that tunnel during orgasm. Either your finger or your pride should feel being squeezed. Try it. :o

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Foreplay is brush and paint, sensation gives you color, sex life is the picture, everlasting creativity will give you masterpiece.

~Sex is an art~