From my perspective, I think the key here is communication between you & your bf. Make sure he knows what you're doing & is okay with it. If he has reservations, try to talk it through & reach a compromise. However, in the end, this is his family. And particularly since the two of you are not married, my thinking at least would be that ultimately the amount of communication you're going to have with his family is up to him. Here are links to 3 articles, from Psych Central's archives, that offer insights into the secrets of happy couples:

The 10 Secrets of Happy Couples

Advice From Happy Couples Part 1 | Building Relationship Skills

More Advice From Happy Couples - Part 2 | Building Relationship Skills