In sociology, homosociality means same-sex relationships that are not of a romantic or sexual nature, such as friendship, mentorship, or others. Wikipedia

A characteristic of socialising with the same-sex predominantly Wikidata

Socialization (social interaction, social relationships) with members of the same sex, as distinguished from sexual interaction with or attraction to members of the same sex (homosexuality) and social interaction with members of the opposite sex (heterosociality). Wiktionary

Sociality with members of the same sex. Wiktionary (translation)