Double vaginal penetration
Double vaginal penetration (DVP) is two objects — two penises, or a penis and a toy — inside the vagina at the same time. Unlike ordinary DP (one vaginal, one anal), DVP puts both in the same opening, making it a notably more demanding stretch. It can be very satisfying for everyone involved, but it needs real lubrication, preparation, and patience, and often only one partner has room to actually thrust. It's most associated with group scenes and appears mainly in porn. It sits at the advanced, high-intensity end of penetration play.
The appeal is extreme fullness and the taboo intensity of a stretch beyond the usual — for the receiver a remarkable sensation, and for a group a charged, shared act. It's often a 'how much can I take' peak experience.
With the receiver relaxed and thoroughly lubed, two partners (or a partner plus a toy) enter the vagina together, coordinating carefully since space is tight and usually only one can move much. Building up with toys beforehand helps the body accommodate it.
This is a big stretch, so go very slowly with generous lube and stop immediately at sharp pain or any bleeding — tearing is a real risk. Warm up and 'train' beforehand, keep separate condoms on each partner to prevent infection, and let the receiver set the entire pace. It's not something to rush into cold.