Welcome to EmpowHER. Thank you for reaching out to our community with your question.
Here is one possibility. When you have sex, the penis can put a lot of pressure on the vagina and on the bladder. The repetitive thrusting motion of the penis going in and out of the vagina gives many women the sensation of having to urinate.
The bladder and its tubing, called the urethra, sit directly along the length of the vagina. The bladder sits closely above the uterus, which is attached to the cervix, located at the very end of the vagina. Since all of these female organs are in close proximity to each other, it’s not surprising that you are experiencing the urge to urinate during sex.