Rocker Nikki Sixx was once left with a painful erection after a stunning model stood him up and wrecked his passionate plans. The Motley Crue star guzzled sex boost drugs Viagra and Cialis after the pretty fan chatted him up backstage at a concert - and then hinted she'd like to spend the night with the bass player. The drugs worked wonders for the hard rocker, but his date didn't show up in his hotel room as expected. He tells, "She came to the show and we had a great conversation and were hanging out. She was funny, witty - and we just felt something. "So she says, 'I'm gonna go do something, and I'll come up to the room and meet you, and we'll hang out, watch a movie.' "I said, `OK,' and I go... 'Give me one of those Cialis things that you guys are taking.' So I take it and she never showed up. That was a painful night."