Its ok if u think about action but if u see as per story she gave many hj,bj previous to liam but no one went more that that, but who had sex or seen her most private part are only 3 -1.nicholas(lost her virginity to), 2.liam, 3.sam(after 20 yrs as per story). Except them no other man saw her full body. So i think still with sam she progressed more.Dylan had already seen sophia naked ..in addition to that, he got a handjob too...so who's leading?
With dylan if she full nude and hj then we can think of dylan crossing sam.