There are lots of different types of drugs - Cannabis, Cocaine, Ecstasy, alcohol. There are three main types; stimulants, depressants and hallucinogens. All of them can affect the way you feel and behave because of the way they affect your brain.
Taking drugs (including alcohol) can cloud your judgement and lower your inhibitions, making you feel less able to make decisions. You can be persuaded into doing things you wouldn’t usually do.
They can affect who you fancy and the decisions you make about sex, such as whether to have sex, who you have sex with and whether you use condoms. You may do things you would not do if sober including putting yourself in dangerous situations or having sex you may regret later on.