Wild one Flo Rida and Nathaniel Rateliff & the Night Sweats, known for the song “S.O.B.,’’ performed during Saturday’s Big Night, the annual benefit for Big Brothers Big Sisters of Massachusetts Bay. The mentoring organization said the party brought in more than $2 million. The night’s honorees were Josh and Anita Bekenstein, who were given the 7th Annual James J. Pallotta Award for their support of at-risk kids. Flo Rida, whose new single is “My House,’’ seemed to have been moved by the event. On Sunday he tweeted, “Boston you welcomed me into your house with open arms #thankyou #bigbrotherbigsister.’’