All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
We have already highlighted that it is permissible for a man to keep his hair long as long as he does not imitate the non-Muslims, the dissolute people, or women, in which case it becomes forbidden. Please refer to fatwas 83385 and 84273.
There is nothing wrong with lengthening the hair in a permissible manner for a correct purpose such as encouraging a girl whom you want to propose to, to marry you, and so on.
Just as a man likes to see in a woman what will encourage him to marry her, it is the same with the woman.
Al-Mugheerah ibn Shu’bah, may Allah be pleased with him, narrated that he wanted to propose to a woman in marriage and the Prophet told him, “Go and look at her, for that is more likely to create love between the two of you.” [Ahmad, at-Tirmithi, An-Nasaa’i and Ibn Maajah]
As-San'aani said in Subul As-Salaam, “Such a ruling is also confirmed for a woman as she looks to the man who proposes to her, as she likes in him what he likes in her.”
Allah knows best.