AIDS is mainly transmitted through sexual contact, the most common forms being vaginal and anal intercourse. Infection is more likely when there are no protective measures in place, such as not using condoms, through direct contact of the sexual organs. Kissing carries a relatively low risk of infection. However, if the kissing is deep and there are significant mouth ulcers or bleeding gums present, the risk can increase somewhat. Overall, the risk still exists but is very low.