Vildo is a fake vagina. Much like a dildo, gay couples (men) that need that extra "zing" in a relationship strap it on and fake-fuck so hard their eyes pop out. There's strap-ons, stick-ons, and many other versions. Some even come with flavours!
Dan: "Oh Edwerd! I'm just not feeling it tonight!! OH BABY I JUST NEED A VAGINA AGAIN."
Ed: "Have no fear Dan! For I have... A VILDO!"
Dan: "Let's fuck hard now via stripping webcam."