if me and my boyfriend having a same ming gua - 8; will our relationships succeed?

Dear Siew Foong, the Ming Gua is used for Feng Shui analysis and reference, not for relationship/ personality/ destiny analysis. Any relationship can be successful with proper 'Human Luck' (personal effort to make things work). Sleeping in a Yan Nian room, or facing your Yan Nian direction, can be helpful. All the best! SN