What is the ruling on using condoms to avoid ghusl, and is thigh sex similar to it? What is the ruling on prayers missed because of that, and how can they be made up if their number is not remembered? Is ghusl for menstruation valid with kohl on the eyebrow?

Ghusl is obligatory upon ejaculation by scholarly consensus, based on the Prophet's (peace and blessings be upon him) saying: "Indeed, water is from water." If ghusl is not performed after ejaculation, the prayer is invalid and must be repeated. However, if penetration occurs with a barrier without ejaculation, scholars differed regarding the obligation of ghusl, and the relied-upon opinion is that it is obligatory. If you do not know the number of missed prayers, some scholars hold that one must make up what one is certain will absolve them, while others hold that making up what one predominantly believes will absolve them is sufficient, and the former is more cautious. As for what is applied to the eyebrows, if it is merely a color that does not prevent water from reaching [the skin], there is no harm in it and its removal is not necessary. However, if it is a barrier that prevents water from reaching [the skin], it must be removed before ghusl and ablution, otherwise, ghusl will not be valid, and the prayers performed before its removal must be repeated.