A pair of glam parties benefited two children’s charities. At billionaire Tilman Fertitta’s posh pad, a hat-clad crowd gathered on Cinco de Mayo for a Kentucky Derby watch party. Event chairs Megan and Luke Hotze and Hannah and Cal McNair were thrilled with the festive turnout of 400-plus — and with a till of $350,000, which went to Bo’s Place. Meanwhile, an intimate gathering at B&B Butchers toasted fall’s upcoming Knock Out Child Abuse event. In September, some 20 amateur boxers — mostly oil and gas honchos, who will train under heavyweight boxing champ Lou Savarese this summer — step into the ring in the name of charity, with proceeds from the event benefiting the Children’s Assessment Center.