Ex girlfriend has embarassing photos of me

Anon or delete please. I recently split with my girlfriend of 4 years because, whilst drunk, I made out with another girl at a party. She later found out about this from one of her friends who happened to be at the same party. About a year before hand she had taken what is a potentially extremely embarrassing photo, which I'm terrified she's going to send to/share with people in our mutual friendship group. As this is (hopefully) a completely anonymous thread I'm just going to come straight out and describe what the photo depicts. The photo is of my very small penis (right on the borderline of being a medically defined 'micropenis') with her ring on it. No doubt people will probably be curious as to how this came about, so I shall give a brief outline. Basically, having been together for quite some time, my girlfriend and I had become very comfortable with each other and the fact that I had an unusually small penis. We would often exchange playful banter about each other and I had no problem with her occasionally making tongue in cheek comments about my size (so long as it was in private!) Anyway, one time when she was giving me oral sex she suddenly stopped and took one of her rings off. I asked her what she was doing and she said she 'wanted to see if it would fit'. It did, and after she had slid it all the way on and had finished laughing and saying how 'cute' and 'pretty' it looked, she said wanted to take a photo. Naively, in my aroused state, I made no objection. But now, of course, I greatly regret not doing so. As I say, I'm incredibly worried that she might share this photo or spread it around. It's not that she's a malicious or spiteful person. She really isn't like that at all, ordinarily. But if she did decide to do so, as an act of revenge because she's feeling hurt or whatever, I would stand to lose basically all of my friends. This is because, as a result of our relatively lengthy relationship, we have a lot of shared mutual friends. And although I was ok with a little playful teasing from somebody I felt very close to, the idea of my whole friendship group knowing about this and collectively ridiculing me is just an absolute nightmare. So my question is, what do you think I should do to avoid this from happening? Should simply apologize for my actions and not mention the photo and hope she doesn't do anything with it? Or should I specifically ask her to delete it/plead with her not to show it to anybody? I honestly think that if this gets out, I'll have to quit uni or at least transfer. :(

Put the internet to work for you. via Personal Recipe 2629979