Back in the mood!

For my boyfriend and I it was a normal day in the beginning. He'd come over and we'd watch movies together, but two weeks ago that changed. There was something in the air and it was calm, loving, caring. He was ontop of me and when he kissed me, it felt like we were the only two people in the world. We haven't had sex before and he is still a virgin so it really felt right. Before we could go any further my mother knocked on the door asking about a power outage in her room and just like that the mood was killed. We've been trying to get it back but have no luck so far. Any suggestions?

I'm 19 and he's 20