"Rolling On The Floor Laughing With You Inside Me"
ROFLWUIM is an extremely creepy acronym used while flirting via instant messaging, texting and other non-verbal communication methods by females and or gay males, in most cases after a joke is told by the person being flirted with.
Like its parent acronym - ROFL, ROFLWUIM can be combined with other acronyms or expanded by adding additional letters.
ROFLMAOWUIM - Rolling On The Floor Laughing My Ass Off With You Inside Me
ROFLWUIMWESWTFBBQ- Rolling On The Floor With You Inside Me Whilst Eating Steak and What The Fuck Barbecue Sauce
Guy: "(insert hilarious joke)"
Flirtygurl57: "You're so funny and cute XD. I want to ROFLWUIM"
Guy: "noice"
Rolling On The Floor Laughing With Tears In My Eyes
Much like its root word rofl, but it offers much more insight into the level of hilarity of the situation. Although yes, you are indeed rofl'ing, you are also doing so with tears in your eyes, which tells the rofl-ee that you found them, their joke, or the current situation worthy of more than just a rofl.
Jake: "He was all like...lawl?"
Mortimer: "...gg"
Jake: "ROFLWTIME!!"