Husband keeping secret

So abt a year ago I was visiting my husbands aunt and uncle out of town so we were all staying with them (myself, my husband, and his two children from a previous marriage) they talk their mom every night and told them where we were and that we had ridden four wheelers. She immediately asked who with, they never responded and later I saw my husband had gotten a text from her saying she doesn't trust his family around her kids and to please keep them safe. He told them he would and that he would die if anything bad happened to them. He told her they slept in the same room as us (which was true)  She asked if I knew the situation and he told her I didn't. At the time I was a little annoyed that he hadnt shared whatever this was with me but at the same time I didn't want to make him talk about an uncomfortable situation if he wasn't ready. Now we are about to go back to this place and we now have a daughter of our own. I'm not sure what it was about but my mind is racing with thoughts and I don't want to put my family in any danger. What should I do?