I can understand that some people want to wait until marriage, and others do not. What they (your parents, your sex ed teachers, preachers, etc...) all fail to tell you is that being sexually compatible is hugely important to the intimacy of a relationship. There are a few exceptions to this, but even then it's really hard on the partner that suffers more from the incompatibility.
Sex is a beautiful and for some people it's easier to share with multiple people than just one.
Now to take up Ygg's point of view. Having been married to a woman which I was completely sexually incompatible with and dealing with the emotional fallout of having been married to a woman who slept with me 5 times total including the wedding night and honeymoon... **** that shit in the goat ass.
No, I won't wait. I refuse to wait. I'm not going to put myself financially and legally on-the-line only to find out that the woman isn't compatible with my needs in bed. This man has been honest, and said he wouldn't wait until marriage. Yet he's the bad guy?
There's no bad guy here. There are two people with needs that seem to be incompatible. So, either he can wait, or he cannot. Either she will sleep with him, or she will not.
There's no malice, no evil, no disrespect. Just differing wants and needs. That's it. Having been married, divorced, and married again I can tell you 100% that irreconcilable differences happen. You cannot resolve something with someone who isn't willing to resolve it. Resolution happens regardless of whether you win, lose, or compromise. But if one person isn't willing to do any of that because it fundamentally goes against their needs? Well. That sucks but it happens.
This is why people can't just pick a random person off the street to marry and make things work out.
Would you buy a sports car that will cost you a lot of money without test driving it? And would that test drive be adequate just tooling around the parking lot? Why is picking a wife or husband ANY different?
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."