I need help bout sex

Lately I've been super horny like wanting to have sex a lot but my boyfriend works a lot and when he is off he is super tired plus we live with his parents and his sister and nephew so it's hard to do anything until they go to sleep which is usually after 11pm and by that time he is either already in bed asleep or ready to go to sleep due to having to get up early for work. What should I do? I hate doing the shit for myself cause when me and him have sex it reaches every need but I'm still horny when he cums and because we don't have sex very much to once in a blue moon he cums fast like 3minites after we get into it.. please help me with any advice?