Thank you for your question. If a person is under the influence of alcohol or other drugs, their judgement can be significantly impaired. They may put themselves at risk, while under the influence of these drugs. Some people simply do not care about getting HIV and other STDs. Some people simply cannot afford to buy condoms and lubricants.
Some people are too embarrassed to buy condoms.
Many people simply do not want to bother using condoms. The use of condoms may not be acceptable in certain religious and cultural groups. In some cultures, it may not be acceptable for a woman to ask a man to use a condom. Some people say that condoms reduce sensitivity, and the man loses his erection as a result. Some people are allergic to latex.