D. -
You seem to have several issues going on here. The first is your age; you're quite young. The second issue is control. I was alarmed that your husband physically "blocks the doorway so [you] can't answer the cell phone when [your] half-brother calls." That's a serious issue that needs to be addressed; you are his wife, not his child. The third, & most obvious, issue is your husband's jealousy over your new relationship. I'd suggest first reassuring your husband that your brother is *not* taking his place, that he is *family* and that you have *more* than enough love to go around. (Just like you love your son & other siblings, but in a different form of love than for your husband.) Also, as others have suggested, get your husband involved in this new relationship - be it phone calls, dinners out, sports, whatever. And, make sure that you aren't taking away time one-on-one w/your husband to spend talking w/your brother, so that your husband doesn't feel neglected. I can relate. At age 21, I married a man I'd been w/since age 14. We were YOUNG & had to learn to be "grown ups" together. I grew up w/three half-brothers & at age 17 met my half-sister. It was hard for *everyone* - my husband(then boyfriend), my brothers - to understand why I wanted to spend time w/this "stranger." But - once I made it clear that *family* was *important* to me, they all learned to back off. And, it was worth it! My sister was in my wedding, my daughter (her niece!) will be the flower girl when she marries next Spring. Good luck. Keep communication open. And - do *not* try to "hide" your relationship w/your brother. Let us know how this unfolds!