Inn to only want her while high?

So I'm in a stable relationship, and so is my best friend (a girl). We hung out for the first time in awhile since we've been busy, and one thing led to another and we got high, which wasn't a first for either of us but a first doing it together. We spent the whole time listening to music and walking around in the woods, and then she asked me to wipe the dirt off the back of her pants. It was a truly innocent request, but I was filled with this nearly uncontrollable lust. I also immediately felt ashamed, so I did as she asked, but kinda made sure she knew I was uncomfortable about it. I don't think she suspects, and we still are best friends, and we're both still in very positive relationships, but is it normal to have sexual desires towards people when they doesn't exist at all while sober?