One idea could be focusing on Spencer's over - protective nature. Since he's highly intelligent, he might research every little thing about pregnancy and drive his wife crazy with all his facts and precautions. For example, he could be constantly worried about her diet and make sure she's getting all the right nutrients.
Another plot could revolve around how they prepare for the baby. They might have different ideas on nursery decoration. Spencer, with his love for books, could want to fill the room with all kinds of educational books from the start, while his wife might have a more whimsical idea for the design.
His friends at work, like Derek Morgan, would probably be really excited. Morgan might tease Spencer a bit about becoming a dad, but also offer a lot of support and advice from his own experiences or what he's seen in his family.
One interesting plot idea could be that Tony and Spencer are assigned a particularly difficult case. They have different approaches at first, with Tony relying on his street smarts and Spencer on his vast knowledge. As they work together, they start to understand and respect each other's methods more, and in the end, they solve the case in a way that combines both of their strengths.
One idea could be that the old friend resurfaces after many years and is somehow involved in a case Reid is working on. Maybe they have some hidden knowledge about the unsub that helps Reid solve the case while also reigniting their friendship.
A more comical plot could be that they are forced to live together for some reason, like a family obligation. Tony's more outgoing and Reid's more introverted nature could create a lot of humorous situations as they try to co - exist. For example, Tony might try to get Reid to go out and party, while Reid just wants to read his books in peace.
One idea could be that Spencer discovers she's pregnant and has to balance it with her academic and personal life. She might struggle to keep it a secret from her friends at first.
One idea could be that Toby and Spencer are unexpectedly pregnant and they have to deal with the reactions of their friends and family. Some might be supportive while others are shocked.
One idea could be that Ashley and Spencer face unexpected challenges during the pregnancy. Maybe their families don't initially support them, and they have to fight for their relationship while also preparing for the baby. Another could be a story where they discover the pregnancy during a difficult time in their lives, like one of them is about to start a new job or move, and they have to re - evaluate all their plans.
One plot idea could be that they discover they are brothers through a mysterious family secret. Maybe there's a hidden inheritance or a long - lost relative that leads them to this realization. Another could be that they have to work together to solve a crime that has a personal connection to their new - found brotherhood, with their different skills complementing each other. For example, Tony's street smarts and Reid's academic knowledge.
A plot could involve the OC using their lip - reading to communicate secretly with Reid in a dangerous situation. Like when they are held hostage by a group, and the OC lip - reads the plans of the captors to Reid without the captors noticing. Then there could be a romantic sub - plot where Reid is initially intrigued by this unique skill of the OC and gradually falls for their personality as well. The OC might also be in danger because of their lip - reading ability as someone wants to keep their secrets hidden.
Perhaps in the fanfic, the OC has a special skill that Reid needs to utilize. However, due to some misunderstandings, he has to handcuff her first. This could lead to a story of them overcoming their differences and working together while the handcuffs become a symbol of their initial conflict and later connection. For example, she might be able to read ancient languages and Reid needs her help with a case involving historical documents.