>> i asked him why he was getting married, and he said at that point it was too late to back out of it. >> the romance lasted on and off for two years. >> what did he tell you about how he felt about you? >> he told me he cared about me. >> dave pietz's lifestyle became the trial here. >> it did, it showed he was dissatisfied with her. >> dissatisfied with nikki, and prosecutors say determined to change her. david went so far as to spike nikki's drink with a club drug ecstasy, hoping she'd finally agreed to that three some. this, according to david's bar buddy, rene stewart. >> he told me he'd put it in her red bull, like when he went to get a drink, and it was just trying to loosen her up together to do a threesome. >> did you notice a change and her after she drink that redbull? >> yes. >> how did she change? >> she became more sexual with people. >> here's a guy who knows full well his wife has addiction problems, and he puts ecstasy