I have 2 kids and I do not want anymore, I tell her that it's my body and my decision but she insists that she gets to have a say in whether on not I get the operation. She wants more kids but I do not, regardless of whether I get the operation or not, I'm not having any more kids...apparently she cannot comprehend this.

She's threatening to not be intimate with me if I go through with the Vasectomy, essentially ending the relationship of 12 years. She refuses to file for divorce but is completely set on cutting me off from sex even if it results in me leaving her.

Update: Thanks for all the feedback, much appreciated! I already have the operation scheduled for a few months from now, I'm hoping that we can talk it out before then and come to some sort of understanding. My hope is that once all of today's hysteria dies down she can come to grips with my decision and maybe even see the benefit in having the operation.