When a lady takes cum loads in the mouth, she is putting herself at risk.

Any micro-tears in her gum line or inside the mouth which she probably wouldn't even be aware of (even from brushing teeth can cause micro-tears) could be a potential "opening" for a virus (most worrisome would be Hepatitis C, Hepatitis B, less likely HIV, but still possible).  These are life-long infections.  Once, "positive" you are "positive" forever.

 Bacteria (most commonly chlamydia, but also syphilis) could also infect her, but there are some protective enzymes in saliva against some forms of bacteria.

Swallowing the load increases the risk as it increases the overall surface area that a virus could find an access point, along the entire esophagus. Once it hits the stomach, unless she has a stomach ulcer, the acid in the stomach would most likely protect against infection.

I Love To Swallow

But you gotta drink the good stuff so I can swallow your protein.

I love the sweetness of cum. Delicious...