How I Met Your Mother's Erotic Musical Number, "Bangedy Bang: Barney's Been Active Sexually" Anderson Evans · 03/09/10 12:14PM J. Lo may have guest starred on last night's HIMYM, but what is everybody talking about? It's Jason Segel's musical performance. The smooth melody of raucous bedroom carnality sprang through his voice in an exciting vibrato... but at what cost?