Origin: "Fat Man" was the codename for the nuclear bomb that was detonated over Nagasaki in 1945. Additionally, it relates to the alternate meaning of bomb, meaning hot, since nuclear bombs are extremely hot.
Yo mama so bomb she beat Usain Bolt's 100m record with her presence
A Bax-Bomb is an explosive asshole. This term refers to a person you don't like and is synonymous with Ass-hole, Dick head, Fuckstick, Shit bird, etc. This term should not be said in a work environment or around children as many will find it extremely offensive.
to drop the initial flirt when talking to someone else online. is usually followed by heavyflirting on both sides.
Stranger: Oh, for sure :) Im very persuasive.
Stranger: In lots of ways ;)
You: thats what she said XD
Stranger: hahahah, of course =P
You: never thought youd be the first to drop a flirtbomb