It is multiple paragraphs, essentially a page or two, of explicit detail, split into 2 parts (Chapter 22, Section 7 for a few paragraphs at the end before a time skip and then continues in Section 12 for a few more paragraphs. The book likes to time skip A LOT)

Absolutely none of it implies the boys engaged in any form of homosexual intercourse. The book explicitly states that their "plan" is to all take turns on Bev.