A/N this is going to be very Anti-beth so if you like her this isn't for you.

Prompt Underestimate me that will be fun

Spencer was reading under in tree in a park near his house one afternoon the breeze wafted against his cheeks and the air was fresh and crisp with Spring. He was enjoying the first of three books he'd brought with him that spring afternoon. That was until he heard an all too familiar voice cry out.

"Ow that hurts." His eyes snapped up and he scanned the surrounding area until he landed on a struggling child and a brunette woman. He quickly jumped to his feet and hurried to the pair. As he got closer he saw the woman had the young boy's wrist gripped tightly in her hand.

He knew the boy and he knew the woman and he saw red. "What do you think you are doing?" he snapped. He grabbed the woman's hand and pried it from the young boys wrist. He bend down to the teary eyed child. "Jack are you okay?"

The boy sniffed. "I am fine now uncle Spencer." He looked up at the brunette woman. Spencer's eyes took the same track. He patted the boy on the shoulder and then got to his feet and glared at the woman.

"What do you think you are doing Beth and where is Aaron?"

The woman sniffed a look of distain on her face. "He wanted to go for a run so we came to this park and that child spilled his juice on my new shoes. I was taking him back to the car."

"That child has a name. it's jack as you well know." Spencer snapped and I am sure he didn't mean to ruin your precious shoes. He is seven kids spill things."

"Yes well Aaron will be paying for these shoes." She sniffed flipping her hair and glaring down at Jack who had taken to standing behind the tall wall that was Spencer.

"Beth you need to leave now." Spencer narrowed his eyes at her.

"Like you can make me." Beth snorted.

A look came into Spencer's eyes one that not many people see. "Oh underestimate me Beth that will be fun. But I am nothing to the hell that you will face when I tell Aaron what you did to his son."

"I'm not scared of Aaron."

"Oh you should be Aaron will die and kill for that boy and he's already proven that so don't push it Beth." Spencer was now nose to nose with Hotch's Girlfriend. "You two are through so you better leave before Hotch arrest you for child abuse."

"Yeah right." Beth scoffed.

"And don't forget it's not just Hotch you have to deal with but Garcia, Morgan, Emily, Dave and JJ. Do you really want to play that Game Beth really."

"Whatever keep the spawn tell Aaron I will be sending him the bill." She flounced off and Spencer shouted at her back.

"Don't hold your breath." As soon as she was out of sight spencer turned to Jack. "Let me see your wrist buddy." He knelt down and took the young boys hand in his. "I think you will be fine but you might have a tiny bruise. "Jack has Beth every hurt you before?"

Jack's lip quivered

"Jack you need to tell me the truth."

"Yes." He sniffed.

"Jack Aaron why didn't you ever tell anybody?"

"Daddy was so happy and he hasn't been that happy since mommy died. I didn't want to ruin that."

Spencer hugged the child to him. "Oh Jack you are the most important thing in your father's life never forget that if someone hurts you, you have to tell your dad or one of the team. Promise me jack."

"I…I promise." More tears leaked from his tiny eyes.

Just then Aaron came running up. "Spencer, Jack wait where's Beth." Spencer's mouth sat in a straight line Beth had to leave and me and you have to have a talk so how about we head to your house."

Aaron could hear the steal in Spencer's voice. "Okay but seriously where is Beth."

"lets just say you won't be seeing her again anytime soon." Spencer glared at nothing as they got into Aaron's car and headed towards his house. Once inside the two adults and the child settled into livingroom.

"Okay now who wants to tell me what is happening to Beth and how Jack came to be with Spencer."

"Well Spencer looked over at Jack. I was reading when I heard jack cry out I of course recognized his voice but couldn't figure out where it was coming from I saw him and Beth so I got up when I got closer I noticed she had Jack's wrist held tightly in her hand and I hurried towards them and released Jack. She told me that he has spilled juice on her shoes and she was mad. She also claims she is sending you a bill for said shoes. I am not happy Aaron I told her to leave before you showed up. She didn't seem to take me seriously but she finally left when I threatened her with the team. I wanted her away from Jack. You can deal with her how you want but I told her to never show her face again basically."

"Jack let me see your wrist." Aaron said trying to digest everything Spencer had told him. He saw the tiny bruise forming. "Was this the first time?"

"No." Jack's voice quivered. "She got mad at everything I did. But you were happy so I didn't say anything."

"Remember what I told you jack." Spencer said laying a hand on Jack's arm."

"Yes you said Daddy loved me more then anything and would want to know or to tell the team."

"Your uncle Spencer is right." Aaron looked gratefully at the younger man. "Don't worry buddy Beth won't be around anymore. But like Uncle Spencer said you are the most important to me.

"You also told Beth you'd die for me and kill for me and you already proved that."

Hotch looked wide eyed at Spencer. "Well buddy he is right now why don't you go hop in the shower well I talk to your Uncle."

"Okay." Jack hopped up from the couch. "Thank you for saving me Uncle Spencer you are my hero."

"You never have to ask or thank me Jack I will always save you." The two men watched the boy leave before Aaron turned to Spencer. "I don't know how to thank you or how I was so blind."

"First of all I will always be there for Jack and secondly you wanted love and she never did it in front of you."

"Still I should have seen."

"Aaron don't beat yourself up. Now you know and you can leave her. Jack is okay and that's all that matters.

"Yes I guess you're right why don't you stay for dinner I can order something."

"That would be great. And without knowing it that was the start of a new family for the hotchner Reid men.

A/N I may add more stories to this universe but I am not sure hope you liked it.