The ATM in ATM sex stands for Ass-to-Mouth, an act where the penis is withdrawn after anal sex and immediately inserted into the partner’s mouth. Depending on personal preferences, oral sex may be provided by the partner who received the anal sex or another party. ATM sex may even be provided simultaneously. Take note that the switch from anal to oral sex is immediate so the penis is not cleaned prior to being inserted into the mouth after it came from the anus. Because of connotations of humiliation and domination, ATM sex heightens sexual excitement. A variation for ATM sex is ATP sex, or Ass-to-Pussy sex, where the penis is inserted into the vagina immediately after being withdrawn from the anus.
Because of the nature of ATM sex, there are some health concerns arising from it. However, when just two people are involved in ATM sex and considering both parties are healthy, you’d be surprised to know that there’s little risk involved since the one who receives the penis from the ass and provides oral sex need only worry about gastrointestinal tract disturbances because intestinal flora is introduced to the upper digestive tract and the mouth. It’s a different matter though when sexually transmitted diseases are in the picture (because infections that would normally be limited to the ano-rectal area may also infect the mouth and throat of the recipient) or when a third party’s anus is involved.
If you’re thinking that getting an enema will help make ATM sex safer, you may be on to something. However, it is not proven that doing so does indeed lower risks. It does help ensure that very little to zero fecal matter is around during anal sex, translating to a relatively cleaner penis for oral sex. The porn industry usually turn to enemas before filming scenes with anal sex but this is primarily to prevent fecal matter from appearing during the shoot, rather than a disease prevention measure.