Andromeda Black was in love with Ted Tonks. But that was the problem; she was a Black, a Slytherin, a pure-blood. He was a muggle-born, or as her family would say a mudblood, a Hufflepuff to boot. If her parents were to have their way, she would end up marrying the likes of Walden Macnair, or another of his Death Eater cronies. No, she wouldn't have it, Ted wouldn't have it, and they loved each other far too much. That was precisely the reason they had decided to elope; there was no way they would ever get married otherwise.
If you asked Andromeda why she loved Ted, she could tell you a million and one, reasons why. When you are raised to be a Black, a pure-blooded, respectable woman of society, hating all others who are anything other than pure-blood, it's not hard to grow to loathe it. It gets hard to become your own person. Things such as blood purity didn't matter at all to Ted; all that mattered was that she was happy, and that they were together.
They were leaving that very night. Leaving to a place that Ted had been preparing for a long time; her family, and especially not her sister Bellatrix, though Andromeda loved her, no one could deny her sister was deranged about blood purity, could find and hurt them. There, they wouldn't have to worry about any of this, just themselves.
This was it; they had just left the Ministry, and were home. Andromeda smiled to herself; the man had been shocked to hear her name was Black, when this got out, her family would be mortified. But, it wasn't as if she cared anymore, as far as they were concerned, she wasn't a Black anymore anyway. Then she realized, she wasn't a Black either way, she was a Tonks; how wonderful.
Then she realized, she would never be a Black again, in body or spirit. She'd never see Bella or Cissy, or her parents, or her cousins, Sirius and Regulus, not even her cousin Evan, who she barely even saw, and didn't really care for. In that moment, it all came crashing down around her, and she broke down. That was the first, but certainly not the last time, Andromeda Tonks allowed herself to openly mourn, something she would have never been able to do as a noble Black lady of decorum. This was how Ted found her, this is why he comforted her; quieting her and letting her cry into his shoulder, never once questioning why she was crying; it something she never would have received from a Black man.
Ted was a wonderful man. Mere hours after Andromeda's breakdown he put on one of his Muggle records; he then decided to play it, and, though Andromeda knew he was a terrible dancer, he invited her to dance. It seemed like a dream. But no, it was all a wonderful reality. This was the man she had married, this was the man she fell in love with.
It didn't matter that she was no longer a Black, all that mattered now was that she was with the man she loved. None of her family's pureblood bigotries mattered to her and Ted here. All that mattered to them was each other. Other than that, who cared?