Nobody knows for sure... but there are a few theories.
1. Security at Wango Tango (WT) is tough, and they make sure that people keep their distance from the performers. Tyrese wanted to bring up girls from the audience and security did not like that, and he argued with them to let them up.
2. He exceeded his 20 minute time limit, and on top of it, he arrived late.
3. He grabbed one of the girl's rear-end, and the show's producers, not wanting to invite litigation, felt it was best to end it right there (so they could then defend themselves by saying they took 'reasonable' steps to prevent any further actions from Tyrese).
Daniel