A Bachur in Shidduchim who has a smartphone with a filter, may he borrow his grandmothers flip phone for the first date to avoid giving a bad impression or is it forbidden to be dishonest?

Rabbeinu Yehudah Hachosid (Sefer Hachasidim 507) rules that one should not conceal flaws from a potential marriage partner, to avoid engaging in a failing marriage. Mori Verbi HoRav Moshe Feinstein Zt’l maintains that just as the Torah (Vayikro 25: 14) prohibits misrepresenting merchandise in order to deceive potential consumers, one may not conceal information in a manner that misleads a potential marriage partner. Yet, it is a common tradition and acceptable minhag for people seeking a Shidach to dress and be seen in attractive clothing and charismatic appearance. Horav Shlomo Miller’s Shlit’a opinion is that it can be done when needed.