I think it means that there's this girl, and she's with her boyfriend. They go into a room to watch a movie or something like that, and he locks the door. She's sitting there with him one minute, holding hands, the next they're lying there, clothes on the floor and cast off to the side, having s*. As she's lying there with him, she realizes she should have saved her virginity; that this was a huge mistake. She wanted so badly to fall for this guy, and she thought he would be the one, and he rushed her into having s*. She couldn't say no, therefore it's like she's under the influence of ecstasy, a club drug, giving this song its name. She isn't really high or anything, she just has strong feelings for this guy, and she doesn't want to ruin the relationship. In this sense, love is just another dance hall drug that will make us do stupid things, and that's probably the message of the song. That's just my interpretatation. I'm not saying it's right, I'm not saying it's wrong. It's just what I think.