When can you have sex with your husband that caught hfmd 11-12 days ago, he's losing all skin on hands and feet ?

Anytime: You were likely exposed as early as a day or so before he developed the disease and if not early in the process. It passes in saliva early on and is in the stool for up to 6 weeks after. You likely had that strain as a kid and are immune, if you haven't developed it this time.Keep him on the couch if you want, but the HFM thing is not something I'd worry about.