Hello, welcome to MythBusters.
No, your vagina cannot get loose from having "too much" sex.
The idea that your vagina will get loose if you have "too much" sex is actually a purity myth historically used to degrade, shame, and discourage women from having sex. This myth implied that the more a woman has sex, the less valuable they are and the more dirty and broken they are. (No wonder so many people feel sexual shame).
Here's what is actually happening:
The vaginal opening is surrounded by muscles that create the pelvic floor. When someone is aroused, these muscles become engorged with blood. And when this happen, the vagina actually opens up.
This process creates space for things like fingers, toys, or penises to be put in your vagina. Some people think of this as your vagina permanently getting "loose," however that is not the case. Because the muscles surrounding the vaginal opening are elastic, you vagina returns to the same size after a sexual encounter. In fact, when someone is not aroused, these muscles are tight and the vaginal opening is smaller.
Another important element of this myth that we need to debunk is the idea that there is such thing as "too much" sex. Many people wonder if they desire or have sex too often or if they want to or do masturbate too often. Scientifically speaking, you cannot have "too much sex." If you start to feel out of control about masturbation or sex, or if your desire for sex or masturbation is getting in the way of living or enjoying your everyday life, you may consider seeking help from a therapist or mental health professional. However, there is no such thing as too much (or too little) sex.