[quote] Is it possible to JOIN with him not being the Host but the guest? I find only the "invite to a group"... Who is the host in this case? [/quote] yes, but they have to be in the lobby waiting for someone to join, which is going to have to be lucky timing for you. plus they have to have their party settings to public. your best bet is to invite them, then give someone else party leader or have them host a new game.