JUST DROP HIM and WALK AWAY.
If you don't, this is what will happen (credit goes to Pinky for this list):
Victim: I know you're not really who you say you are.
Scammer says: Oh baby, why u say dat?
Scammer thinks: Damn, she's onto me. I wonder how she found out so fast?
Victim: You've got pictures of a model. You don't look like a hard working contractor.
Scammer says: I be bossman baby my mens work in the cornsturctstion.
Scammer thinks: She's right! I better find a pic of some white dude who's working construction.
Victim: You say you graduated from USC, but you're not listed on the alumni list and you don't write like you went past 5th grade.
Scammer says: What u mean baby? Must be mistake, I love you baby, ur so bootiful.
Scammer thinks: I will google that alumni list and pick a new name from there and that's who I will be next time. Oh and I can get Brudda Ogomooko who went to university to study English, to write me a better script to cut and paste, or maybe I'll just scam the Europeans for awhile. Their English isn't much better sometimes.
Victim: You say you're in West Africa but your IP address came back a proxy server in Argentina! What's up with that?
Scammer says: it my frien computer and he from argentina...don u belif me baby...you need to turst me i love u baby
Scammer thinks: I have to tell my oga to get off the proxy servers once we've established the location as Africa.
Victim says: Tell me the name of the orphanage and who's the sponsor of it. Who's paying you?
Scammer says: you need to turst yor man more i gots to go to work now
Scammer thinks: It shouldn't be hard to find some orphanage here or on the net. Or maybe we can get a nice fake web site built. The Chairman just bought some new credit card numbers so we could even buy a domain. That would really make our scam look good.
Victim says: All of the above.
Scammer thinks: Dammit! This one got onto us fast. I better search and see if she's posted our information anywhere to warn away others. Dammit! She did. Okay, I'll just take 15 minutes out of my scammy day and make a new profile, using all the new things I learned from TM. Suntanned, ordinary looking guy, check. Change my name to USC alumni, check. Get better script, check. Find a desperate European woman, check. Use an email account without an IP, check. Make a fake website, check. I just love my helpful jobs.
However, if you just drop him and walk away without a word, you will leave him looking stupid and confused, he would not know what he did wrong, what was his mistake and why all these hours (weeks, months) of his time invested in you were a waste.