How can you tightly your vagina?

Hello everyone!

I want to ask you a question. How can you tightly your vagina back up? O know it will not go back the way it was, when I was virgin. I had heard that you can use vinegar to tightly your vagina? Do that true? If not, then what I can I use to tighty my vagina. I want to make sure when me and boyfriend go all the way, that the sex will be great. And I also had heard that the more you have sex your vagina would get lose. And I don't my vagina to get too lose, that my boyfriend don't want to have sex with me.