Yes, sometimes, it is natural to experience awakening of sexual desires in the process of meditation. It is because our mooladhara chakra which is the centre of our sex energy, and our aagya chakra, which is the center of our awareness, come into connection with each other when we meditate. These two chakras are internally connected to each other. They are two polars. So when you meditate then your aagya chakra gets awake and with it mooladhara chakra also begins to awake and because of it you begin to experience strong urges of sexual awakening.
If you meditate on aagya chakra, you will experience subtle vibrations on mooladhara chakra as well, it happens because of this interconnection. Another reason sexual desires awakened in meditation is that mooladhara chakra and kundalini shakti are located very near to each other, so when because of meditation kundalini energy awakens, it also touches the mooladhara chakra which becomes the reason for sexual arousing. Actually it is a signal of good progress in meditation to feel sexually activated.
You only need to be watchful during this period of time and need to be alert to not to follow your increased sexuality, just be observer and soon this awakened energy will find its way upwards and all the energy will transformed from mooladhara to higher chakra and you will become free from extra pressure. But remember not to go into sexual activity, otherwise which energy was meant to be transformed to higher chakras, will go waste.
vinodhan,