SUBREDDIT: r/relationships
TITLE: I [19F] tried to help my close friend [18F] out with her crush [18M] and it totally backfired. Where do I go from here?
POST: One of my closest friends in college has been really into this guy from the first week of school. They've been super close friends and it's always bordered on romantic. I kept telling her to make a move but she was so timid, she was afraid he'd reject her. She actually decided to end their friendship last week because it was too weird.

Today, I asked her to dinner and he ended up tagging along with her, which surprised both of us. I hadn't spoken much to him before but he's actually super cool, and we all really hit it off as a group. We stayed at dinner for almost 3 hours.

After we left, she told me she had to figure out what was going on and stop clinging to false hope. So I kept telling her to just ask him what their relationship was heading towards but she wouldn't do it. Then she devised this plan where I would ask him out and say "I don't want to intrude on whatever you guys have," which would get him to elaborate.

I know, this is a really immature idea but I'm pretty shameless and I was willing to sacrifice my pride to help her out. So I friended him on Facebook and asked him out...you know where this is going.

Of course, he responded saying he'd love to and he's super glad I said something because he's really bad at putting himself out there. He also said that there's "nothing to intrude on."

Now I'm in this position where I can't just tell him it was a joke. That's mean and deceitful. There's also a part of me that does really like him and feels like I deserve that for going for it. And of course I feel awful for my friend and don't want to jeopardize our friendship. What should I do?
TL;DR: 
My close friend suggested I ask out her other friend to assess their relationship. It backfired because he said yes. Can I go out with him or is that really insensitive?