What is the ruling on men tying their hair, or part of it, even if it is short, such as tying hair from the top "like a fountain"? And is this considered imitation of young girls, and does it entail a curse, as in imitating adult women?

The criterion for blameworthy imitation between the sexes is performing an act, whether it be related to clothing or appearance, that is customarily specific to one gender. Al-Haytami, in "Az-Zawajir," explicitly stated that men imitating women, and vice versa, in matters customarily specific to them, such as clothing, speech, or movement, is a major sin. He based this on the hadith narrated by Ibn Abbas (may Allah be pleased with both of them): "Allah's Messenger (peace be upon him) cursed the men who imitate women and the women who imitate men." Therefore, if a man tying his hair in a particular manner is, by custom, specific to women, then it falls under the prohibited imitation; otherwise, it does not. It is important to note that, in principle, it is permissible for men to tie their hair.