I go online he goes offline?

Ok guys I need some input I have been trying to hard to figure out why when I'm talking to a guy that I like via texting things start off good but get confusing. When i come online he goes offline within a couple of seconds i observed this pattern many times can u tell me why? I like him and he doesn't know it :/
I realize he waits some extra minutes to respond because I usually respond hours later (he knows I'm sorta busy) .
Also I've noticed a few times when I texted him and then I see him go online but no response then he goes offline and text me back later? what does this all mean? I don't expect him to respond ASAP but when he has the time but what's the point of going online then going offline and hours later responding?

Thanks guys for your answers.
I go online he goes offline?
Post Opinion