wtf?????

so everything my boyfriend and I have sex the condom always breaks and we never go hardcore because we are so scared of it breaking. last night I was riding him and stopped and go off and then when I went to sit back down I wasn't fully on and I felt it tear and then he pre came but I don't think he did it in me because when I went to take the condom off that's when he pre came. why do you think it breaks everytime? we have tried out multiple condoms too