Thank for for detailed reply.
When I said it could be a cultural difference, I meant what he did and what that action was viewed or interpreted by the victim was different. I don't have the police report yet, so I can not say much what she said. But when my father-in-law was sitting in the park he was doing breathing exercise (breath in in one nose while covering the other nose by hand and then breath out from other nose). He did that 4 or 5 times. And then while sitting he put his hands inside the trouser pocket.
I'm not quite clear on what you are referring to when you say the "other" nose. I got the sitting part and the breathing in part. It's the part where he is covering the "other" nose that I start to doubt the accuracy of the image I'm visualizing in my mind. Well that and the reason for his hands being in his trousers have got me thinking that it may not be so much a cultural difference as it is a difference in the slang we tend to embrace when we describe certain parts of our anatomy. For example, most American's are familiar with what is being referred to, when someone mentions a trouser trout. In fact, as another person mentioned on this thread already, "pocket pool" is also a type of slang to describe what activity one might be engaging in with the "trouser Trout".
However neither of the actual things being referred to, have any literal relation to playing a game of pool or what fresh water sport fish are routinely stocked in public waterways.
Likewise, I have to believe that when someone is telling me about doing breathing exercises, which require covering one nose, then the other, in a sort of back and forth repetitive movement,,, for which that person has enlisted the use of his hands to accomplish said nose squeezing activity, which happen to be in his pants during this public ventilation exercise,,, well let's just say that it sounds like a self serving, generally private activity was taking place in a public park and you're father was caught red handed,,, so to speak.
Now I don't know what is considered an acceptable stage for engaging in this sort of activity in you're native country, but in this country, it is usually a private or semi private location, with usually one or possibly two consenting adults in attendance throughout the entire performance. If there is more than one adult in attendance during this heavy breathing exercise, you can be sure they are very acquainted with each other and didn't just happen to run into each other at a local bird sanctuary or public park.
What I'm getting at is that it wasn't what you're father was doing that is unacceptable, it was the location he chose to do it at, that landed him in trouble with the law. So you should explain to you're father, that in this country, when he's in a public location, he should keep his hands out of his trousers and completely away from his other nose.
In every state of this country, the only nose that can be blown in public, is the one on his head,,,, the head located above his shoulders,,, the one with two eyes, two ears, a mouth where food is inserted. Tell him that in the future, he must only enjoy this activity at home. Doesn't matter if it's before or after his walk in the park, just as long as he's at home, he can legally open the barn door and spend quality time petting his pinto pony, having a flag raising ceremony or playing snake charmer for as long as he likes.
Hopefully old habits aren't so hard to break. Maybe you could get him a camera so he has something to keep his hands busy when he's out in public?