From Voyeurweb's Wiki

[edit] DPP - Double Pussy Penetration

This is the way many hot wives like to accomodate the starving cocks of their lovers in a good MFM threesome experience. In general, DPP could be arranged with a cock & dildo pair but the best result is reached with two thick, hard & hot male cocks.

For a detailed explanation on how to arrange a good DPP party for your wife, see DPP Game