I think I am very misunderstood around here. I point out facts and make observations about human behavior without making any moral judgements, and people assume that I am endorsing said behavior. I'm not saying it's right, I'm saying it's true.
I never claimed that men were not capable of love. I am pointing out that boys will often say things like "If you love me, you'll do it." or "Don't you love me? I want you to prove it." or "I love you so much, I want to show you." Do you disagree that boys do that?
Not all boys, obviously, but most have said or will say something like that at some point in their life to get a woman into bed. The boy may actually believe what he's saying as he says it, but really it's his procreation instinct at the wheel. That is an example of using love to get sex.
Afterwards, he may lose interest in her and not really even know why, because his animal instinct has relinquished control and his logical brain is back thinking "dafuq just happened?" Or he may stay in the relationship because he knows he can continue having sex with her. Love certainly plays a part in this, but I think you're underestimating the importance of sex to men.
How long would the average man date a women who didn't "put out"? Two weeks? A month? Six months? The point is, not very long. This is assuming the man is not a virgin, of course. Virgins might wait a much longer time because they don't know what they're missing out on.
How many men would stay with their partners if they suddenly decided to stop having sex with them? And for how long? If it were your wife, you may have developed such a strong bond that you don't want to leave her, but can you honestly say it wouldn't put a serious strain on the relationship? What if she was just your girlfriend? Would you stay in the relationship, get married, knowing you will never have sex again?
Of course, I forget who I'm talking to. You're saints. Paragons of virtue and chivalry. You would never abandon your true love over something so trivial as carnal pleasure. But that is confirmation bias, and doesn't prove it wrong regarding most men in general. It only means there are exceptions. Think about your friends, not just your Good Guy Greg best friend, but all of your male friends. Think about the jerks you know that aren't your friends and imagine what those guys were like as teenagers. Do you honestly believe that not just a few, but the majority of them, would stay in a sexless relationship?
Admittedly that's an extreme example, but plenty of relationships crumble and fall apart from a reduced frequency of sex, let alone a permanent embargo. I think it shows that sex for most men is more powerful than love.