Friends Partner - Do I tell her??

[LondonLife3]

Earlier today a friends partner started to message me, being very odd give me his number basically saying they weren’t together sending loads of kisses ext
They are together, I’m not sure if I should say anything…
I don’t think he knows how long I have known her, as we all worked in the same place years ago but I have known his partner since school

I would just tell him to back off or you will tell her

A proper friend then yes I would tell her, just someone I know of but aren't close with then I probably wouldn't.
I wouldn't reply or engage in a conversation with him either.

Yer I blocked him now as I don't need any drama

I would tell her, otherwise she might spend ages with a cheat/someone who wants to cheat.

I would tell her because (I don't mean this to be dismissive) if he is texting you out of the blue how many other women has he texted during their relationship?
The poor woman could be meeting women on a regular basis who know her partner is cheating/trying to cheat on her.

I would definitely tell her, give her a chance to book an appointment at the clinic.

He sounds the type to be playing russian roulette with her sexual health.

No question.