The ultimate form of bisexual intercourse involving both sexes,(usually in a threesome) simultaneously. This requires the usage of the vagina, as well as the anus.
As the girl experienced vaganal for the first time in her life, she realized that she regretted becoming a bisexual...it just wasn't good.
Using a bottle opener in the skin between the vagina and anus, removing the skin and creating one large hole. This process is painful but definately worth it for the sex. Vaganal sex is when a penis is inserted in this hole. Lubricant may be required.