Accidentally saw a text i wasn't supposed to see...

I guess I just want to vent right now about this.

Last night I had my college graduation party at my house. It was pretty small with just about 20 people. I got pretty drunk, and since my boyfriend's best friends were also at the party, he was hanging out with them for a large majority of the night. We've been together for nearly 8 years so we're not exactly attached at the hip anymore so him hanging out with his friends and me hanging out with my friends doesn't bother me at all.

At some point during the night, I came up behind him to give him a hug. I didn't realize he was texting someone, and I innocently glanced at his phone. All I saw was that he was texting his cousin, who said "WHAT? YOU SHOWED [name of a family friend] THE RING?" I quickly closed my eyes because I really didn't want to read any more of the conversation but I know I already saw too much. I'm so angry with myself, even though I apologized to him for seeing what I saw, and he said "I showed her the one that you want."

I'm freaking out though because it seemed like a coverup in his tone, and we are going on vacation next week. I feel so horribly that I may have partially ruined the surprise. I don't know, I could just be overthinking it, I do that a lot. I just hope I didn't ruin anything and thus discourage him...