Your body goes through a lot of changes due to pregnancy. However the tightning of the vagina is normally not a change most women will experience.
There is no possible way. If you want your vagina tighter do kegel exercises.
Men normally view the "bum" as to be tighter then the vagina, because it's normally not used as much as the vagina. The tighter the hole is, normally the more pleasurable it is for the man.
There is no other way for a mammal to get pregnant, besides the vagina.
Nope, only boys can get girls pregnant
If what you mean by close back up, is get tighter after intercourse, or the time it takes for your vagina to retract back after continuous intercourse, it usually varies with every woman. If you are looking for a quicker method for that closness or (tightness) of the vagina, you can always put vinegar in your bath water and soak for a little bit. This will contribute to bringing the vagina tighter.
Yes, if the ejaculatory fluids came in contact with your vagina you can get pregnant.
Generally yes since they are typically more petite than the rest of the world.
Semen has to be inside the vagina for you to get pregnant.
yes, you can get pregnant
It's rare but it can happen but all you have to do is exercise those muscles. Normally the body compensates after birth and the vagina gets tighter then before birth.
No; sperm must enter the vagina to get pregnant.
A virgin female can not become pregnant by manipulating any vagina, hers or another person's.