Model Stephanie Seymour hosted a lavish baby shower for Julian Schnabel’s pregnant fiancée, May Andersen, on Saturday. Seymour and artist Schnabel threw the coed shower at his West Village apartment. Andersen, a 30-year-old model turned art-gallery assistant director, is nearly six months pregnant with her first child. She had been dating Schnabel, 61, since last April; they got engaged in November. Sources said at the shower, attended by guests including Julian’s art dealer son, Vito Schnabel, that Julian unveiled a 20-foot artwork he painted of May naked and pregnant. One source said, “When guests remarked how amazing the painting was Julian said ‘May is an amazing woman.”’