The licking could initially be a source of confusion for Peter. He might not understand what it means exactly, which could cause some tension in their relationship as he tries to figure it out. But once he realizes it's a sign of her care, it could enhance their bond.
This interaction might also create a more possessive side in their relationship. The Black Cat's licking could be her way of marking Peter as someone special to her, and Peter might start to feel a sense of protectiveness towards her as well because of this unique form of affection.
One possible plot could be that the Black Cat licks Peter Parker as a form of affection, and this becomes a unique way for her to show her feelings in a world where their relationship is full of secrecy and danger. Maybe it's a sign of trust she's building with him.
In many fanfictions, their relationship develops through shared experiences. For example, they might start off as allies in fighting crime and gradually realize their feelings for each other. Then, as they get married, they learn to trust each other even more. They rely on each other's skills, like Peter's spider - abilities and Black Cat's agility and thieving skills in some cases.
It affects his ability to be Spider - Man. Without a stable home, he has no place to keep his suit or his web - shooters. He might have to carry them around all the time, which could be risky. Also, it can make him more vulnerable mentally. He's used to having a home and a family (even if his aunt may be struggling too), and now being homeless can be a huge blow to his confidence.
His life would change in many ways. First, he would need to be more present at home. No more staying out all night as Spider - Man. He would have to ensure Black Cat has proper medical care, which might mean finding a doctor who can be discreet about their identities. Also, he'd need to start thinking about finances. Babies are expensive, and he can't rely on his meager reporter salary alone. He might have to take on more side jobs or find ways to earn more money legally. Emotionally, he'd be a bundle of nerves, constantly worried about the safety of Black Cat and the unborn child.
It can strengthen their relationship. The kiss might be a turning point where they become more than just allies. They start to trust each other on a deeper level and become closer partners in fighting crime.
It can affect his powers. For instance, if he has a head injury near his spider - sense area in his brain, it might make his spider - sense go haywire, either being overly sensitive or not working at all.
It could be a bit of a comical interaction at first. Peter, being the more down - to - earth and sometimes clumsy New Yorker, might accidentally break some of Shuri's delicate Wakandan equipment. Shuri would be exasperated but also find Peter's innocence endearing. As they get to know each other better, they would start to have deeper conversations. They might even joke around about who has the cooler superhero/tech - genius identity. Peter could call Shuri 'the Wakandan wizard' and Shuri could tease Peter about being a 'bug - boy'.
It often puts him in great danger. Hydra is a powerful and ruthless organization, so Peter has to be constantly on guard.
It could also make it difficult for him to be a reliable superhero. If he's sleepwalking at random times, he might not be able to respond to emergencies in a timely manner. His allies would start to worry about his ability to protect the city.
If Peter is spanked by a fellow superhero in a fanfiction, it could lead to a sense of resentment at first. But later, he might realize that it was for his own good and grow from the experience. It could be a catalyst for him to better understand the superhero code and become more responsible.