The Bug:

You can invite the same player multiple times to your realm even if they've already received an invitation or have already joined it.

Steps to Reproduce:

1. Navigate to the minecraft realms menu.
2. Click on your realm and hit the "configure realm" button.
3. Click on the "players" button.
4. Invite a player to your realm who has already joined it and take note of how you can invite the same player multiple times to your realm even if they've already joined it.
5. Invite another player to your realm.
6. Invite the same player again and take note of how you can invite the same player multiple times to your realm even if they've already received an invitation.

Observed Behavior:

You can invite the same player multiple times to your realm even if they've already received an invitation or have already joined it.

Expected Behavior:

You would not be able to invite the same player multiple times to your realm if they've already received an invitation or have already joined it.