An ejaculation so powerful, it can't be held back and explodes across the room. Or in the case of a blowjob, causes the blower to gag a little from the sudden blast at the uvula, and leaking. During intercourse, it gushes out from the openings. Also known to break condoms.
Jack: Dude.... That girl sure knew how to blow....
Jason: Say wha...?
Jack: It was so good, I had an ejacusplosion and she almost choked!
Jason: DAMN! O_o
John: Dude... I'm in trouble...
Frank: Why?
John: I... may have gotten Jessica pregnant?
Frank: WTF! Why didn't your dumbass use a condom?!
John: I did.... My ejacusplosion blew a hole in the tip...
Frank: ._. ....
When youaccidently press the send button before you've finished typing the full message. Can occur while texting or email.
Guy 1: "Oh, man I just texted my girlfiiend that "I'd love to have a b"
Guy 2: "What?"
Guy 1: "Yeah, I didn't get to finish the sentence cause I accidently had a premature ejacusend. I was going to tell her I'd love to have a beer with her. "