I wanted to share my experience with you, to give you the other side of the coin. I'd also like to emphasis that in my case there was a criminal prosecution and the person involved pleaded guilty (and now has a criminal record).
In late 2010, I was Christmas shopping in my local shopping centre with DS2, then around 8 months old. I had several bags hung off the back of his buggy; when I was in the queue to pay for my parking, I took my hands off the buggy to slot the coins into the machine and his buggy tipped backwards (DS2 was unhurt). I bent down to pick up the buggy and check on DS2, and as they do my jeans pulled down a little so that the top of my knickers showed over the top of my jeans.
As it happens, the security guards of the shopping centre had noticed DS2's buggy topple backwards and we just commenting to themselves how hassled I looked, when they noticed that a man behind us in the queue was taking a close interest in me/DS2. He took out his phone and took what turned out to be several close up photos of my bottom as I bent down.
After I paid for my parking, he followed me into the lift and got out at my floor, saying he'd noticed the buggy thing and asking if I needed any help. I, thinking he was a perfectly normal person, politely said no and walked to my car. He followed me to my car, taking several more photos of my bottom on the way.
The first I knew was when two of the security guards made a citizen's arrest on him, and escorted me to my car. Although I had known nothing was happening at the time, I was quite distressed when they explained what had happened.
A policeman took my statement that evening, and then several days later i heard that whoever was responsible for deciding whether to prosecute (CPS? I'm not very familiar with the terminology) wanted to make something of a test case of it.
As PP say above, due to the public nature of the place where the photos were taken, what the man did wasn't a sex crime per se. Instead the man was charged under a pretty obscure piece of 19th Century public order legislation. The offense he was charged with 'outraging public decency'. In other words, the 'victim' under this offence wasn't me, the person being photographed, but the general public who could have been distressed at a man taking sexualised photos of an unknowing woman. It seems the fact that no members of the public were distressed was irrelevant - they could have been.
Anyway, the man pleaded not guilty, so we went to court and it was listed in Aylesbury in June 2011. Luckily for me, he changed his plea to guilty 10 minutes before the case was due to start. The judge described him as a dirty old man, and he got a fine of £650 plus costs. But, to my more importantly, he got a criminal record.
If anyone wants to look up the case, it's Regina V BULLOCK.
Sorry for the long post - but I wanted you to know that what your DP did was a criminal act (albeit one he is unlikely to be prosecuted for).