蓦然回首那SB竟然还在
[mò rán huí shŏu nèi sb jìng rán hái zài]
'Suddenly Looked Back Only To Find That Guy Still There'. Here 'SB' is actually a rude term, meaning fool. In fact, this Internet slang phrase humorously refers to situations that one thought a particular annoying individual would leave, but unexpectedly they didn't; leaving behind an unpleasant impression again.