Too tired to have sex

My boyfriend and I are on very different work schedules. I work later than he does, so when we see each other, it's literally just to sleep. I love him and love just curling up beside him and sleeping. But he's always too exhausted to have sex with me. It's been a month now. We've talked about it and we both want sex, but he never gets enough sleep as it is. No matter how tired I am at the end of the day, I still want sex. Is that immature of me? I would never make him feel bad about it, but I do feel a little sexually neglected. Has anyone else had to deal with this kind of situation and what did you and your partner do?