Photo: Netflix You can’t have Temptation Island without Mark L. Walberg. The two are synonymous: He has hosted the series, which drops both members of a rocky relationship into separate houses chock-full of sexy singles, across two decades and three television networks. But amid a sea of somewhat removed reality hosts, Walberg is one of the few who isn’t afraid to leap into the drama — or reveal his own vulnerabilities in the process. Every time a couple gathers at the bonfire to watch clips of