I really need advice

My best friend who is straight and also I'm fucking in love with, his wife, and I had our second threesome. And I'm a bi guy by the way and they both know that I like him. The first time it happened we were all completely fucked up drunk, and he said I better not touch her at all only him.The second time though it happened we only had a few drinks and he said I want to see you fuck her and that she better make me cum.I really just don't know whether doing this will completely destroy our friendship or what like I really don't know what to do.