[Spoilers Main] Dothraki Mating and Does George Understand Sex?

I'm rereading AGOT and got to the princess's wedding to the Khal. There is sex and fighting and then sex and fighting combined but George writes that two guys were fighting over a girl then they battled and one got killed and without a moments pause the winner took the woman and started mating right then. I know its a small thing but are we to assume he had an erection while in mortal combat then just went right into sex?