Portuguese underwear model Renato Seabra was hauled into court in Manhattan in his sensational castration-murder case yesterday, wearing a snappy gray suit — a gift from his mother, who’s been visiting him three times a week in Bellevue’s psychiatric prison ward.

“For a man charged with murder in the second degree, who’s never been charged with anything in his life, he’s doing OK,” defense lawyer David Touger said of Seabra, a model in his native Portugal who has made previous court appearances wearing rumpled prison garb.

Seabra, 21, is charged with strangling, bludgeoning, and castrating — with a corkscrew — his fashion-journalist sugar daddy, Carlos Castro, 65, during a January quarrel at the InterContinental Hotel in Times Square.