i think
perhaps
this song means;
he's moving (or trying to move on). He's moving away or trying to move on from someone he can no longer truly be with. He maybe likes this person but truly he likes "being with" this person. As in he likes the sex i do believe. and so, he says he will cross this line with this person one last time before moving or moving on. Perhaps, he just means to spend the night with, have sex, or maybe...that one last kiss.
i think perhaps this song means; he's moving (or trying to move on). He's moving away or trying to move on from someone he can no longer truly be with. He maybe likes this person but truly he likes "being with" this person. As in he likes the sex i do believe. and so, he says he will cross this line with this person one last time before moving or moving on. Perhaps, he just means to spend the night with, have sex, or maybe...that one last kiss.