I don't know if there's really an analogy for this.
I hate to use this word but often it's a bit violent. When I get down on all fours on my yoga mat, my dog Pluto knows that's his invitation and he's on me in an instant and there's no mercy unless I stop him. There's no foreplay either.
After a couple somewhat gentle test strokes to align himself to my vulva he'll make contact and from there he holds on and jackhammers until he's fully erect and all the way inside. I often feel his scrotum banging around my clitoris, which adds to my pleasure.
The internal pressure I feel increases with each stroke as things get bigger very quickly and once he's full length he shoves in all the way with all his might to where there's a lot of pressure around my cervix and he's definitely pressing hard against the tippy top of me inside. At that point he holds still so his knot can swell the rest of the way, creating even more pressure between us. He's a tight fit by the time he stops thrusting and it gets much tighter from there. There's significant pressure between us.
Likely, I've orgasmed once or more by now. I can easily feel his higher body temperature inside me as well as all over my fanny and back. His fur is somewhat long with a heavy undercoat and that is brushing all over my skin throughout all of this and is electrifying. His breath is hot and moist and I can feel it on my shoulders, neck and sometimes my head depending if his head is in line with our bodies or not.
During this, Pluto has a singular focus and nothing distracts him. Knocks on the door, the phone, doorbells, noise from the TV, nothing. He's making puppies and he's on a mission.
If all has gone well, his knot will be fully inside me and swelling to it's limit and my vagina opening will have surrounded the little bit of shaft between his knot and his body. The fur he has there is shorter and more bristly, tickling my labia which adds to the electrifying sensations I described above. When he's done thrusting he usually rests on me while panting and I can feel his chest expand and contract on my back, as well as his fur moving all over me. I'll definitely be far in orgasm-land by now.
He'll ejaculate several times and with each he'll twitch inside of me which I can feel every nuance of because of his higher body temperature combined with the intense pressure between us. Once he's done ejaculating he'll often just remain in place until his swelling goes down a bit and can pull out with ease. Usually that doesn't hurt too much, but it depends how early he decides to start pulling away. We've remained "together" like that as long as 40-45 minutes, but usually it's 15-20 minutes.
Sometimes he pulls out way to soon and that really hurts. Sometimes he'll try to turn around and in doing so, most of the time he ends up pulling himself out and that also hurts. Once in a while he managed to turn around and remain inside me and that is just soooooooooo wonderful. When that happens, we'll be like that for a really long time. Though, one time he managed to flip around and we were stuck together (I'll get to that in a minute) and he started trying to walk away which really freaking hurt so I crawled backwards with him but after a short distance he pulled out and the pain.... ow....
There have been times where we were legitimately stuck together. This comes from a combination of things including timing: his sheer size, how wet I am (I get super wet anytime I'm aroused), and how much of him gets inside me creating either a vacuum situation or a hydrolock situation, maybe both, my being athletic/fit and having done kegals and yoga my entire adult life, etc. It doesn't happen consistently and most of the time he remains in me after ejaculating by his choice.
There has been times where he kept thrusting past his knot reaching a certain size and then he can't get it into me and instead his huge knot will be pounding away on my labia which is a totally different set of sensations. I tend not to orgasm as intensely from that though I've likely already had a few from his jackhammering so I can't say its bad because it's not. It's merely different. The thing is if he doesn't get his knot all the way in, some of his ejaculation will be inside me, some of it will be outside me all over the place. A few times he tried to shove it back in too, not that he could get the knot in during the second round either.
One thing about Pluto that's very different from any dog I had been with in the past is if he started to tug to pull out I can say "No!" and he'll instantly stop and go back to resting on me for a while. He's very consistent with that.
