Thick White Smoke through exhaust after refilling AC refrigerant

I am getting thick white smoke when I fill the AC low port with refrigerant. When I drain it, the white smoke goes away. Anyone have any clues about what it is? I assume it is oil going into the intake through a vacuum line. Faulty vacuum switch for AC? Misplaced Vacuum lines?

 

That is strange. Never heard of this issue before. Usually white exhaust smoke is an indicator for a blown head gasket but the fact it goes away after taking the freon out throws that idea out. From what I remember though there is no exchange between the a/c system in the engine though. Only contact they make is the fact they are bolted together and the belt that drives the a/c off the engine. No vacuum lines or anything. Not real sure what could be causing that