You may believe it or not... Most women like their orifices to be simultaneously penetrated. This can be done either with 2 fingers, a finger and a sex toy, two toys, a penis and a sex toy or two penises. In case you want to use a sex toy, make sure it's made out of soft, pliable material.
For some women it's quite easy to accommodate things in vagina and anus.
For others this procedure leaves much to be desired. They need extra stimulation, relaxation, plenty of lubricants and practice.
In fact, that depends on the size of those objects that a woman is willing to insert in her tight dark tunnels. If you want to experiment with two penises or dildos, be careful and never force.
If you introduce a sizable accessory within one of your openings, the membrane that separates your vaginal and anal cavities makes another entry tighten. So, if you insert a large dildo within your vagina, the anus tightens. And vice versa.
Now you have to find that combination that brings you real satisfaction. There are different techniques for you to try out and find the perfect one.
Start with inching a finger or penis in one entry and a finger in the other hole. Make delicate, slow motions and alternate between the two until you experience enjoyable sensations.
Before engaging in any anal exploration, make sure your nails are cut to short to avoid injuries. The receiver is asked to use enemas and douches to empty the anal cavity and eliminate unpleasant wastes. Have lubes nearby to make penetration more thrilling. Never be selfish, use condoms and trust your partner!