+1 for Cougar’s post from me too.
As a 32 year old female, I can’t get a tubal litigation. So speaking from experience as a childfree woman, yes, it is difficult. But the “aww, but you’ll change your mind” bingo gets chucked at women probably more than it does men, because we are seen as being more emotionally volatile and subject to the whims of our biology. My GP was shocked when I talked to her about sterilisation and I hadn’t had any children. I was tempted to ask her which rock she’d been living under the past 20 years, and did she know how many people were choosing not to have children these days?
However, fortunately for me, I can take pills/shots/have an implant to have control over my own fertility (or, preferably, lack of it). Men can be subjected to “the oops” and therefore, for a childfree man who wishes to remain so and have an active sex life, whether inside a committed relationship or casually, or whatever floats your boat, the only way to make damn sure of it is to have the snip. There are women out there who will use a guy as a sperm donor and then sting them for child support 9 months later, and there are women who change their minds and either engage on a long and tiresome project to bring their reluctant partner around to the idea of having a child, or just go for the “oops” option and assume that “he’ll love it when it gets here”.
If you’ve had the snip, then you won’t get the long and tiresome “babies are great” project because you don’t have the capability. Therefore, she will go away and find someone else to produce a baby with. If a one night stand turns up 9 months later with a baby, well, the joke’s on her and she needs to go on Jezza Kyle for a DNA test. And the oops option, unless for some unlikely reason the snip didn’t work, or grows back together, is also not going to happen.
So yes, I absolutely understand why the OP would want to have the snip done.