Sex during ur period is safe, but like u mentioned it is messy. I've never had sex on my period, because I think it's gross. But from the looks of it, it's a turn on for ur bf. & I think u should do it if u want to do it, not just to satisfy ur partner. But remember if u ain't the one satisfying his sexual fantasy, some1 else will. :/ It's sad, but it's true.