Voidable Contract: A Tricky Twist

Kya baat hai, I still remember this question from a previous year's AP LAWCET paper: "Can a minor, who has entered into a contract for purchasing a bike, on reaching majority, refuse to deliver the bike to the seller?" Section 27 of the Indian Contract Act says a contract with a minor is voidable at the option of the minor. So, if the minor has entered into a contract before attaining majority, he can refuse to perform his part of the contract after attaining majority. But, what if the minor had already taken delivery of the bike and enjoyed its use? Can he still refuse to deliver it?