Oh Lady Teddy I don't think its an odd occurrence at all. It's an expression of emotion and a sign that you've given yourself over to the pleasure you're experiencing.
I frequently use a Tantric orientated technique in my post examination 'treatment' (though I don't claim to be a Tantric expert) whereby I will attempt to channel sexual energies from that huge errogenous zone, the whole body, into the abdominal and genital region.
I will, with agreement, take a patient right to the edge of orgasm a number of times, probably half a dozen, backing off 'jus a la moment critique' but keeping contact.
It's not unusual for the patient to reach a giggly or, more commonly, a sobbing crying state and its at that point they will finally have a crashing orgasm.
The giggling is not a sign that they are particularly amused nor is the sobbing and crying an indication that they are unhappy. Like the physical sensations of orgasm they are signs of release, this time of emotion.
So Lady Teddy, look upon your display of emotion as a sign of your pleasure. My every Good Wish!