A big part of your speech therapy is going to be acceptance, losing that shame you feel toward it, and removing the need to hide it. In short, you'll need to be open with him about your disfluency to even do therapy properly. In fact, he should be a part of it. I couldn't imagine not having the support of my husband, reading the news to him every morning for practice and feedback, and occasionally even having to lean on his fluency when my own disappears (though never too much, verbal independence is very important). I think by keeping this from him, you're doing him a huge disservice, too. You're hiding a big part of yourself from someone who is probably 110% ready to accept all of you. Give him the chance to do so.