This is when a girl is hogtied or frogtied, preferably with a ballgag, and you stick a vibrator or some other stimulating sex toy into her vagina and turn it on. The pleasure will make her orgasm, forming a Volcanic Milky Blossum.
When having BDMS with Sara, Robert frogtied her and gave her a Volcanic Milky Blossum. She was exposed with her clothes off and naked and Robert jacked off to the sight of her helplessness.
The act of blowing your load into a girl into your partner's asshole and having them put their legs behind their head and farting your splooge out in the air like a volcano.
The act of defecating into an others mouth whilst having sexual intercourse. The person who's mouth is shat into then slowly spits out the excrement to create the illusion of an erupting volcano.