Well I am putting myself in your shoes... and it would be irritating to me too.
If that were my Husband, I KNOW he would find it irritating too. BUT, my husband WOULD say something to the women. That is just the way my Hubby is. PLUS, any women friends/co-workers he has... ALWAYS shows respect to me first... asking how I am and to "..please tell Susan sorry for inconveniencing you, but this was work related etc.," So these women are not "using" my Husband for idle-chit-chat and "socialization."
OR, maybe these women are just "text-addicts" (which nowadays there are many who are just addicted to texting) and they can't stop. So they text anyone who they know socially or work wise.
Work is work. Any other contact beyond that, is not work related. If, like my Hubby who also works on weekends too sometimes, the office has to contact him. No problem, fine. BUT, beyond work topics/needs... well, it's just social idle trifle irritating contact. Which is NOT necessary.. and especially since your Fiance says they are not his 'friends.'
At least, your Fiance tells you this, and shows you the texts, right? Or does he just tell you what the texts say? If the women are not improper, there is no reason not to show you it.
These women seem to have nothing better to do, than to text the whole world like they have nothing else in their lives.
Some people just like to keep work and home-life/personal life, separate. It should be respected. Co-workers do NOT have to contact each other on the weekends OR after-hours. What the heck for?
Anyway, I asked my Hubby and he said he LOATHES extraneous chit-chat texts like this... and HE would just tell the women...and that his cell phone number is for work issues, that's all... AND that it causes a disruption in his off-hours and home life. And anyway, HOW did these women get your Husbands cell-phone number anyway? Unless they have no privacy of personal contact numbers, through their HR department.... um...
Well all the best, just my & my Hubby's thoughts,
Susan