That response has nothing to do with whether or not he decides to marry his girl. He can decide not to have sex with NFL groupies without deciding to get married at 23.
And FYI: getting married does not somehow magically stop NFL groupies from throwing themselves at him; it just increases the penalties if he decides to have sex with them. (see: Woods, Tiger; Bryant, Kobe)
Sure it does. He doesn't have to go chasing pussy as he's got someone at home to give it to him. And maybe, just maybe, he's one of the ones who takes his vows seriously