Sorry if this isn't the right forum for this but here is the exact scenario that I have faced for the last two evenings:
1) I create an open Xbox live party
2) One of my friends (lets call him A) joins the open party
3) I then make the party invite-only and then I "Appear Offline"
4) A friend (let's call him B) on A's "Friend list" goes to "Social" on his xbox dashboard, then "Friends" and then "Parties", selects the party A is in (which happens to my invite-only party) and then simply joins it. He is given the option to join a party that is invite only.
I couldn't believe it so I had him repeat this multiple times last night. At first I thought it might just be a glitch with the party last night but it happened again tonight.
What am I missing here? No one is inviting B to the party and yet he is able to join. B happens to also be on my friends list but since I appear offline he can't really see who is in the party with A just that someone is there.
Any ideas what is going on here?