Was there a reason you were so graphic?
It's a thread about libido. If you're discomfited when discussing sex in an open and transparent fashion, maybe you shouldn't click the thread?
Is it to demonstrate your awesomeness as a partner? By demonstrating sexual prowess?
Neither. You've obviously missed (or completely ignored, whichever) the point that partners sometimes do things that are of no personal benefit or pleasure, simply because they benefit their OH. I'm not sure how I can make it any simpler.
It does strike me on MN how many men gravitate towards the sex topics though, proportionally, in comparison to the minority of men on the forum in general. Yet on the sex threads there are loads of them.
Wonder why.
Maybe because Mumsnet can often be an echo chamber of women making assumptions and generalisations (usually negative) about men, how we think, and sex? And some of us find this a little frustrating? Also Sex is a topic that equally involves men and women. 50-50. Both genders are required and sex is something I have personal experience of, and therefore feel able to express an opinion about it. I can't say the same about the childbirth or pregnancy forum. I read them, but don't have much to say because shock, horror, I've never been pregnant or given birth, and never will. However they're useful info for when/if my DP and I decide to go for kids.
If you think arguing with people on a forum about sex is somehow erotic or titillating to me, then I'm sorry to disappoint you.
The fact that you describe men as "dogs without bones" pretty much tells me everything I need to know about how you view my gender. I wonder how you'd react if I called women "bitches in heat"? 
Not really called for, is it?