My bf wants to cut his penis off

A`Vi
We got into a arguement like a year ago and I said I didn't enjoy the sex out of spite but I didn't think he would be so affected. We've been on and off for almost 4 years and he says he wants to get married and have kids but he still wants to go through with cutting it off in the future and just go to satisfying me with his hands. What should I do ?