Martens are strongly introverted and so need a lot of time alone. They dislike being put in a position where they have to talk to people they don't know and as such don't gain friends very often. Too much social activity can be really stress-inducing in high doses, especially if it involves crowds, loud noise or being put on the spot. When put in that sort of position, a marten will almost always become irritable and withdrawn, and will likely leave at the first possible opportunity.
Martens really resent being made to feel as if they have an obligation to spend a lot of time with people, so they are likely to struggle with outgoing friends who are not respectful of their need for space and quiet, and will probably outright avoid emotionally or socially needy people.
A marten requires friends who understand that not always being enthusiastic about spending time together does not mean that they don't want to be friends.
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Martens really resent being made to feel as if they have an obligation to spend a lot of time with people, so they are likely to struggle with outgoing friends who are not respectful of their need for space and quiet, and will probably outright avoid emotionally or socially needy people.
A marten requires friends who understand that not always being enthusiastic about spending time together does not mean that they don't want to be friends.
Source