Lyric discussion by JamesMathieu 

I feel like this is about two people that were in a relationship together, broke up because they weren't seeing eye to eye on the course that it was taking them, tried to be friends, then found themselves at the same place as last time.
"I will sell you a future you don't want like I did last time . I won't go slow." She is saying that just like the last time they were together, she will want a more serious relationship than the other person is after. So she is wary about going ahead. But because she loves this other person, she is warning them of what will happen if they get together again.

"Taking every chance to find solutions that never make anyone happy" The other person is trying to offer compromises for both of them. Maybe she wants a more serious relationship whereas the other person just wants a friends with benefits situation, so they offer a middle road: dating. In the end, it doesn't make either of them happy cos it isn't what they each want.

"I will change direction. I will tell you that everything's moving too slowly. Just another lie. One more intruth" She's finally done with this cycle they seem to be going through, so to end things more quickly, she makes herself reveal her true feelings faster than she would have otherwise. OR she is going to act like an extreme version of herself and pretend to want even more than a serious relationship, maybe bring up marriage even though she actually doesn't want that or just pretends to seem like she wants more of a serious relationship than she does.

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