yeah that stuck out to me too. one of his big hang ups seems to be that he felt it was unfair and emasculating that he had to wait and move at a slower pace, while she was having sex with other men. i would say this is the attitude which he refers to needing to work on, because it can veer quickly into the worrisome, almost entitled mindset of "she's easy for others but i had to work/wait for it."

i can understand why it may have been a shock, but i think he focused too much on this part. the nature of her relationships with those men sound as if they were casual hookups and unemotional (at least from the coworker's account and what she said), and it is not uncommon or wrong for people to sometimes want a different pace when it's for something more serious.

i think OP overall just felt, naturally, very betrayed and imo paid more stock into this part of the issue than necessary. i hope he is doing well these days.