Of course. It's not a matter of true love, but discipline and faith in your relationship. Sometimes even in the best couplings there are moments of doubt and certainly every day is not perfect. But if you believe in your partner and the love you have for them, there is no reason why an occasional crush or second look should interfere with your self control. Cheating tends to occur when a relationship hits a rocky point and the people involved are not willing to communicate effectively enough to fix it.