When Chandler returns , he declares that Whitfield is in his seat , culminating in his demanding the professor 's underwear .
Over the credits , Prof. Sherman Whitfield ( Peter Dennis ) joins Ross 's table to congratulate him .
When Chandler returns , Ross declares that Prof. is in Ross ' seat , culminating in his demanding the professor 's underwear .
Over the credits , Prof. Sherman Whitfield ( Peter Dennis ) joins Ross 's table to congratulate him .