'Drop Dead Diva' Sneak Peek: '90210's' Trevor Donovan Drops Trou in Court (Exclusive Video)

90210 alum Trevor Donovan bares more than his emotions in Sunday's Drop Dead Diva.

The actor guest stars as Keith, who is described as possibly the worst "best man" ever. Under his watch, the groom ends up across the border and then in prison.  

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Keith ultimately comes to his friend's rescue with an embarrassing courtroom confession, which leads to him dropping his pants in open court, as seen in this clip, which is exclusive to The Hollywood Reporter.

Donovan is best known for his role as Teddy Montgomery on 90210, which ended its four-year run on The CW in May.

Sunday's episode marks the summer finale for Drop Dead Diva, with new episodes scheduled to return Oct. 6. Diva, from Sony Pictures Television, airs at 9 p.m. Sunday on Lifetime.