Hurt emotionally

My husband gets turned on by thinking of me with another man. It is killing me inside. I took our kids to the beach today and I asked how his day was at work and he came clean and told me he started to touch himself at work (in the bathroom) thinking of me with another guy at the beach. I'm also supposed to go to dinner with my friends this Saturday and he asked me while having sex if I'd go get laid before I come home. What????? Why??? Who does this? Is this for real?