It’s harder than you think.
2The condom needs to be worn the WHOLE time.
avert.org
In order for condoms to work their magic, they need to be worn for the entire duration of the sex — even if you’re also using another method of birth control. In one recent study, only 59% of people who used condoms with another birth control actually kept the rubber on the whole time. (The rest of them put it on after some genital contact or took it off before they finished.) This is a big problem, because any skin-to-skin genital contact can lead to STIs. So put it on right at the beginning, and keep it on until you’re finished.