Just how many illegitimate children does Mark Sloan have?

It’s no secret Mark was the biggest horn dog the show ever had and is on record sleeping his way through the whole nursing staff (plus Callie) but the show never really seemed to address that he’s more then likely got a brood of Sloan children running around out there. They kinda addressed this when his high-school squeeze shows up with there daughter Sloan Riley who Mark thought she aborted and then of course Callie had Sofia so Mark is definitely quite the fertile stallion! I’m actually surprised the show never did a storyline when one of the interns turns out to be the product of one of McSteamy’s many conquests! I actually thought it could have been the case with Casey Parker since he kinda resembles Eric Dane.