Forum highlights on Penetration:

I can never seem to orgasm without clitoral stimulation, is that normal?
I can never seem to orgasm through just penetration. I've always needed some kind of clitoral stimulation to orgasm. I know where my g-spot is. It's.

Urethral Pain - Frustrated
I know I've posted about this before, but I have a lot of pain around my urethra during penetration and I am so, so, so frustrated! 2 days ago, I...

Having a bit of vaginal tightness during sex... any help?
I have been having some vaginal tightness while having sex with my girlfriend, which makes penetration pretty difficult despite the fact that it is...

Ladies, can you orgasm from penetration alone?
I am curious how many of us can achieve orgasm without other stimulation. I cannot and I wonder how different it is.

anal toys for double penetration
I am interested in finding a toy for double penetration. I looked into a bunch before I was a little overwhelmed and undereducated. What would you..

There are many possible answers. Since you seem to be new to harnesses and are talking about a single dildo I'm assuming that your a man and your penis will be the other "toy" (my apologies if this is wrong).

You're going to need to decide which item goes in which orifice and if a particular position is important to you. I'll come back to this a little later.

Many standard two-strap"jockstrap" harnesses can be worn with the dildo projecting above the penis. There's even a harness (the Ulti-Mate harness link ) that has a cutout section in the pad to make it easier to use. In any case, you'll probably want a harness with a pad under the dildo so it is less likely to pull your pubic hair.

If you want to wear the dildo so it projects below your penis then things get a bit tougher. It's likely that there's a harness out there somewhere that can

The positioning of the dildo affects the sex positions you can use. With the jackstrap style harness (limiting this to the more common sex positions) you can either do missionary/woman on top with your penis in her anus and the dildo in her vagina, or doggy style with the reverse. It sounds like your dildo is pretty big, so you'll have to figure out what she's comfortable with. If it has a flange (enlarged base on the bottom, a realistic dildo's balls work as well) it will probably (95%+) work in a O-ring harness. The material is not ideal, though - Pleasureskin is porous so it's hard to keep clean and it may contain phthalates and other possibly nasty chemicals. If you decide to use it you probably should put a condom on it.

If an 8" toy is close to the maximum that she can comfortably take alone than you might want to go a bit smaller for DP, since you're putting two toys right next to each other and your control isn't going to be quite as fine as it is with a single toy. At least for starters you might want to get a shorter and narrower toy to give you a bit of wiggle room. If you can afford it I'd definitely recommend 100% silicone, you'll be getting a toy that you can use for the rest of your lives that can be easily cleaned. Decide on a rough size and what style you want (degree of realism and amount of texture), and think about what you'll be using it for. Then look around - the only thing you need to have is a flanged "harness compatible" base.

You and your girlfriend have a good point - if you're worried about mess it's much harder to have enjoyable anal sex, but you might not have a problem. Many times stuff doesn't hang around in the rectum, and if you're wearing a condom you don't need to worry about UTIs (and she doesn't have to worry about what your semen might do in her rectum). If she's still worried, though, there are several options. Firstly the shouldn'ts: you shouldn't use any chemical laxatives. If you do, her intestines will be irritated for a while.

My advice would be for her to use the toilet, wash off (either with a shower or a wet rag), and then do a trial run with a dildo that's about as long as your penis is (use a condom if you're using a porous or possibly chemical-bearing dildo). Grease the dildo up, work it in, and see if there's a problem (she can do this on her own if she'd prefer). See if there's going to be a big problem. If she still feels she needs to clean out, then your best bet is a rectal douche (small enema). Use only plain water - no soap, no commercial enemas, no other additives except possibly a little salt or baking soda. There is a pretty good discussion here (link). If you do go the douche route, then I'd recommend looking into either a squeezebulb syringe (or a repurposed Fleet-type bottle) or a Higginson syringe (harder to find but easier to work with). You can also use an enema bag, but you need to be careful how much water you inject (if you get too much in things get a bit more complicated, and it takes longer for all the water to come out).