I am not getting the Leave Conversation option in Group Messaging in iOS 8

Hello tchadden,

This option is only available if there are more than three people in the group iMessage or if the group message uses MMS.

Leave this Conversation might not be available if there are only three people in the group iMessage or if the group message uses MMS.

Send a group message with your iPhone, iPad, or iPod touch
http://support.apple.com/kb/HT5760

Cheers,

Allen

tchadden,

Thank you for using the Apple Support Community. Due to the nature of your issue or question you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/GetproductgroupList.action.

All my best,

Allen