There is no such thing as "girls' semen".
Any sort of discharge or semen from both the male and female pubic areas that have a strong odor, is itchy or has a weird color is abnormal. Pubic discharges should have little or no color and odor, and should not itch. If you have any of these symptoms, consult your doctor. You may have an infection.
No, It smells like it used to...
Not right away. After a while, semen can take on a fishy odor, though.
Discharge
You mean "Semen", which is the fluid that carries spermatazoa out of the male body. Semen after a few minutes can smell somewhat "fishy", so I suppose it could do the same in someone's mouth.
nothing.
Only males can produce semen.
That is normal. The sperm changes color a little and consistency as the enzymes in the semen change.
I'd say for the most part they do it to please their partner. Guys love when there girl trulyacceptsall of them and swallows their semen. And some girls just love to give head and like the taste of semen.
from girls semen and it tastes great
Yes, most girls do love a man's semen. It is not the best tasting stuff, but knowing they are pleasuring the man makes it all worthwhile.
That is a personal question for specific girls. Some do, some don't.