If your friend knows your boyfriend, then I'd give his answer a little credence but otherwise LMo has been through similar so her answer is plausible too.

Next time my boyfriend said anything about my divorce, I'd take a light/curious vein and asking him, "Why do you ask about my divorce so often?" If you are brave, you could head him off at the pass harmlessly and say something like "You want to ask me to marry you or something? Cause I'm not ready for marriage yet if that's what it is. . ." or something along those lines. I'd throw in a "I love you it's marriage I'm not ready for" kind of explanation too, just to make sure he understands that your relationship with him hasn't changed.