In dissociative identity disorder, is it possible that the host n alter appear at the same time?

like when i am chatting using two IDs at the same time, the first ID is the alter and the other one is the host? they are not interact with each other but with other people simultaneously... and of course they are two distinct personalities, with different manners, typos, styles, voice, history, etc. Is it also possible that the host is the one who is aware that there are some alters?