is there really a different risk in terms of having the cum in your mouth versus just swallowing it? I mean if its in your mouth then you are open to your body absorbing it, and if it goes down your neck and into your stomach its killed even more there (well not much survives the acids in your stomach, one of the strongest type known to man! so how does your stomach survive itself then you ask, magic )

so if you do cim you may as well swallow

give me a good reason why not in terms of documented risk then.