Welcome to HCM
I think most of the time nausea
after sex is unrelated to it. It might be your subjective feeling.
Nausea may be due to stomach upset
, which might be exaggerated during sex as result of pressure on the stomach.
I advice you to speak with your girl friend, whether she has any stomach upset or reflux disease. Treatment will be over the counter available medicine like antacid
, h2 blockers and ppi's will be helpful.
Rarely the nauseas feeling after sex is usually caused by either a hormonal
imbalance, or from the cervix
being hit continuously during sex.
It is unlikely as you have not mentioned any previous incidents.
I advice you to treat the stomach upset if it is there. The problem should resolve on its own in week or so.
I hope i have provided the information you needed.