What do I do? It is long but I need help?

My husband of over 2 years has NEVER lied to me before. But today, he told me he wanted to go to the mountains to see how pretty the snow is up there. We took our 12 week old son with us. He called my cousin to come with us because "he didn't want to be alone if we broke down". Then my cousin invited 3 of his friends to come with us...(calling my cousin raised flag number 1 but the extra friends...flag number 2) My husband didn't know about the friends though so he says. So I was excited but also skeptical. Turns out I had good reason. His idea of a snowy mountain was rocky terrain. We had to go through a stream and a huge load of big rocks and then it was a long and rocky trail! Not even that much snow. I told him he lied to me and he denied it. He said that he told me that there was a rocky trail. (he did tell me that but implied that it wasn't what I thought which was a 4 wheeling trail...my husband likes to go 4 wheeling by the way, which is why I was skeptical) I have been very firm in the past in saying that I didn't want our son to go 4 wheeling with him, especially at this age. Turns out, also, that the 3 friends were drinking and driving, again, my husband didn't know about them or the fact that they would do that but still made matters worse. He keeps saying sorry that he ruined the day for me because I thought it was going to be romantic but I don't know what to think. He says he didn't think much about the fact that there were a lot of rocks and didn't realize he was lying to me. He denies manipulating me altogether. Should I believe him? What do I do? This hasn't ever happened before.