Re: the embolism, that poor woman has become an urban legend! The only way blowing air into the vagina could cause embolism and death is if you were less than a week out from a c-section and she still had a significantly unhealed wound inside her uterus.

FWIW many women get gas in their uterus (methane) after a c-section, due to post-operative infection and THAT could well have been the cause of the poor woman's demise, rather than the air-blowing sexual practice.

OP as others have said, air being sucked into and expelled from the vagina is usually down to position and is harmless (apart from making you blush maybe).

Bx