Should I end my engagement to explore my crush?

I was madly in love with a boy for around three years, but he was with someone else at the time. I thought he would never be interested in me, so I began dating someone else. My boyfriend proposed to me a week ago, and I accepted, but only just found out that the guy I had a crush on is now single. What should I do? Should I end this engagement and at least try asking this guy out to see if there can be something between us? I'm confused. I don't want to regret not giving it a shot. I feel bad for my current boyfriend, but I owe this to myself. What should I do?
To begin with, if you can have doubts about your engagement a mere week after agreeing to marry someone, I hate to point out that this doesn't really bode well for the future of this relationship. You are discussing ending something on the basis of the fact that someone you had a crush on may reciprocate your feelings. You have no idea what this person is like, whether or not he has any interest in you, and whether he is even going to consider a serious relationship with anyone, considering he has ended the one he had with someone for three years. You don't even know him as a person, considering the fact that you have never actually spent any time with him. Are you really going to throw away what you share with your boyfriend for something based on so much speculation, just so you don't regret it later? I suggest you stop watching cheesy romantic comedies and think long and hard about what matters to you.

My boyfriend insists on my wearing clothes that don't show off too much skin. I think he's being overbearing and over-protective, but he insists it's because my locality isn't safe. How can I convince him to let me be?
Your body. Your clothes. Your prerogative.