Dave Potter/Tonks had known about his true family since he was 5 years old when Tonks had told him the truth his mum and dad were Lily and James Potter both killed by Lord Voldemort and only his younger brother Harry was left living in the fight at their old home sadly Dumbledore refused to allow Harry to stay with the Tonks' and Andromeda refused to allow Dave to move in with the Dursley's as unlike Harry he did not have the bond of his mothers love to keep him alive.
Now the 18 year old auror in training had found a way to save his little brother from the hell hole that he called home he could adopt him and Dumbledore had accepted this as a good idea and he put one roadblock in the way which he thought would work Dave would have to be married before he could adopt Harry. Which lead him to be being back at the Tonks residence as he knew Tonks was home for Christmas as Dave normally visited the Weasley's with Harry as it gave him some time with his little brother
"My brother from another mother" Tonks said pulling him into a hug "how are you?"
"Annoyed" he said truthfully "remember my idea to adopt Harry?"
"Yeah?" Tonks said "the old man say no cause I will go and curse him to death if he did"
"No he said it was a good idea" Dave said "I have to be married first"
"What a load of old shit" Tonks said "that is so unfair"
"Yeah" Dave said "that is because he knows I won't do it before Harry is old enough to look after himself"
"Marry me" Tonks said at once she had always had a crush on Dave and she figured this was the perfect time to prove it and maybe it would amount to something more and maybe he would feel for her half of what she felt for him it would be enough for her.
"What?" Dave said confused
"Marry me" Tonks said "for Harry you need to marry someone marry me we are best friends it is not that much different apart from kissing and sex really"
"Your serious?" he said to make sure as you where never really sure with Tonks
"Yes Dave Potter" she said "for the safety of your little brother marry me"
"Ok" Dave said and pulled her into another hug
'I am marrying my best friend' he thought to himself 'for Harry'
'I AM MARRYING DAVE POTTER!' Tonks thought 'FOR HARRY AND FOR ME'