It depends on lots of details. Photos normally belong to the photographer, but there presumably must have been some kind of understanding or agreement what would happen with them when they were taken, too.
If they're being broadly shared and you find that damaging, you can pursue it legally -- especially if your name is on things. If it's someone sharing them with a single other person and they're not being posted to the web, and you posed for them, it's a little trickier. If they're photos this person didn't even take themselves, they're engaged in copyright infringement on top of things.
Anyway, you'd need to contact a local attorney and they're going to need to get into a lot more detail. On a practical level, once photos are out there on the internet, they're out there. You can stop things if they're only at the email level. You can also generally stop further distribution happening, and try to keep your name off stuff. And if stuff is out there on the web with your name on it, it's permanent damage and you can sue the person who did it for quite a lot.