This thread makes me feel uncomfortable.
I'm sorry for your loss, first and foremost. However, do you think your grief could be clouding the issue? Anger at losing your mum seeking a place to land?
At the end of the day, your DW went to a hen with your permission. Hens by their very nature can include events leaning to the bawdy sexual persuasion. I agree with pp that for a hen do, the nudity can be more amusing than sexy.
She drew a naked penis and had a laugh while doing so. Unless she made sexual contact with the model, I don't think you have anything to worry or be cross about. I also highly doubt the model was "getting his jollies".
I also think you have gone slightly ott in the hoping no one finds out. It's a hen do and a live drawing class.
Also, you can't really control what other hen guests wish to post on the Internet. It's a pretty common thing to do nowadays.
To summarise:
The hen do
Your mum and your wife's relationship
The sad passing of your mum
Are all unrelated, but you are convoluting them in your head, and should try to untangle it all.
Again, sorry for your loss
I don't think they are unrelated how can they be in the circumstances. I would have been unhappy anyway despite what happened to my mum as I think its tacky to be in the presence of a naked young lad at my wife's age and what transpired after the so called artistic life drawing. Lets get this quite clear its a stripper in what ever form which you wish to dress it up and is done for pure titillation purposes as was proved by photos and comments on facebook. That's fine to some with those sort of inclinations and this is what happens on some hen dos but I thought my wife was better than that these days at age 57, but to brush it off as some sort of casual whats the problem type of thing to me is quite offensive. If I had done that with a young girl I know what would have been said about my morals and values All of this happened at the same time and you seem to suggest that these type of events are everyday things. Just being there drawing a penis to me is bad never mind what was going on with my departed mum and that's my opinion.
All of these things are related unique events which happened at the same time which will stick in my memory for a long time if not forever. We as a family my 3 sisters and me are interring my mums ashes next month laying them next to Dad who died just 2 years ago at 86 same age as mum.
thank you for your condolences though