Vaginal Odor when he actually cums inside?

Are you sure you do not have a bacterial infection like BV?

His semen is fuel/food for the bacteria living in your vagina.will affect the growth of the bacteria. There are both good and bad bacteria. Normally the bad bacteria have a feast on his semen and they are the ones causing the stink. In a healthy vagina, the good bacteria will however keep the bad ones in control.

My suggestion is that you see your doctor to make sure the bacterial balance inside your vagina is healthy. If it is not, it is easy and quick to treat with antibiotics.

Do not douche. It can (and likely will) make matters worse. If your bacteria levels are balanced, there is one douching system that use clean water and gravity that might help and are different from the others in major ways. It is called 'waterworks'. Just Google it. It is very cheap and does not use chemicals.

I also think it is your vagina and your rules. You have to live with the smell and wonder if other people can smell it too. So you get to decide if he may ejaculate inside you. He should at least respect that, right?

Best of luck!