TV
The pop princess, who has long been a gay icon, will play camp Jack's sidekick on his talkshow Jack Talk after Out TV is bought out by a Christian TV network.
Spears' character is described as a "Christian conservative" - at least, until Will and Jack loosen her up.
The episode is due to air in the US in April.
Other stars who have appeared in Will & Grace include Cher, Jennifer Lopez and Michael Douglas.
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