Perri was leading something called a “Relationship Detox,†and it DID seem. Sweet: Matt Smith is proud that his good pal, Billie Piper, supported him backstage. Pip/MR Piper/M Pippa/M Pippin/M Pippo/M Pippy/M Piraeus Pirandello Pisa. Gain strength and shed pounds while you work through Billy's hardcore boot camp. Sweet: Matt Smith is proud that his good pal, Billie Piper, supported him backstage.