This is an older discussion, but I want to chime in as I'm a total geek about max vaginal depth (yes, I'm a guy).
First, the most common reason for burning is that the material the dildo of made of might be burning you. Those low priced jelly dongs have been notorious for that problem. After being sure the toy is a better material, check into your lube. Does it irritate your vagina with longer and deeper usage?
Uterus and cervix position can vary from one woman to the next. A number of women have a uterus that is retroverted. That can make deep penetration uncomfortable. If the long penis or toy slides up beside the cervix, it should still work out just fine.
Next, the vagina varies in size just like every other body part. Mostly though, since the vagina is so elastic, it is the bones of the pelvis that end up being the limiting factor, along with discomfort up beside the cervix or the cervix itself. So, some women will have a more shallow pelvis, and while others will have a deeper one. We can't really tell this just be looking at someone's body, with some exceptions though. The penis or toy does not go up into the abdomen. It goes on an angle towards the small of the back. That's why the tip eventually might reach what feels like a wall, to a well endowed guy. That's not the cervix. The cervix feels like the tip of a nose. The wall is the upper back side of the pelvis, or the sacrum.
A few people gave some very good advice. A couple of those I'll put in this list.
- Get very highly aroused. Not only does the cervix raise up and inch or two, but your pain threshold will go up by 100% + according to studies.
- Softer dildos and real penises bend into a big arc, and also squish down a little bit. Aside from higher arousal, that's why a larger real penis might appear to fit inside.
- Start exploring the deeper spots and walls of your vagina with a glass (pyrex) or steel dildo. Feel around a lot. See what spots feel good to you. Push in front of the cervix ( the A spot ) and up the rear wall to the deepest spot (posterior fornix ). Those spots feel good to a lot of women, with moderate pressure. Try a slow thrusting, but only pulling the dildo out an inch before pushing the deep spot again. Learn how it feels to touch right on your cervix, but also deeper up in a fornix near it. (no the cervix is not like a bottle cap on top of a bottle, in most women ).
- Press that glass or metal toy very rearward and feel the tip of your tailbone, or just up from the tip. Now, trace the tip up the rear wall of the vagina to the deepest spot. If it feels like you are pressing against a solid wall up there, and you can almost bop it on the pelvis up there, that is your max depth. If it does not feel so firm, you probably can gain an inch or two in depth over months of trying to relax and stretch in deeper.
- Do use narrower, but not too pointy, toys to begin depth exploration and learning. Like others said, switch to thicker and thicker toys gradually.
The average distance from the lower edge of the pubic bone to the promontory of the sacrum is about 12.5 cm, or 5 inches. The entrance of the vagina is lower set than that. So, that adds and inch or two of potential depth.
That is why so many vaginas max out at 6" to 7" of depth, with a few being 8" deep, and very very few being 9" deep.
Remember, the real penis and many dildos bend into a big arc or squish down some. That's why we see many optical illusions combined with occasionally seeing a vagina that is really deeper than average.
Happy toying!
