When something truly disasterous happens.
Boy: Wanna get freaky?
Girl: For sure, have you got protection
Boy:No, But its all good
Girl:I dont think so...
"That chicks got a really nice body but a ratsbum face".
Getting final Killcam'd on COD... Ratsbum
Finding out your wife is cheating on you is very Ratsbum.
"I see you stood in dog shit...Ratsbum"
Stepping in a big puddle is Ratsbum.
"Entries may be edited and become the property of Urban Dictionary"....Ratsbum!(small print at the bottom of page!)
Opposite of Un-Ratsbum (see Un-Ratsbum)