Sex with ex

Well we're already past the awkward stage (meaning we actually hangout as friends but with a lot of sexual chemistry) the break up was over silly things and I want him back but the thing is I don't want to come off desperate. Lately I've been super duuuuper horny and I wonder if sleeping with him will backfire, what to do? Should I just unleash this inner sex goddess and pretend nothing ever happened afterwards or bury my desire for now? Also, what's your opinion on casual sex?