Should i tell his wife?

[Erica]

I met this Spanish guy about 2 months ago in Dubai.
I live here and visits every week for business. We got on very well and after our third date we slept with each other, the passion was just INCREDIBLE.
The messages he sends me are so lovely, my friends have met him and they all agreed how lovely he was - they seemed quite jealous about our chemistry.
I am 22 and he is 32... While laying in bed he asked jokingly if i would marry him saying i was "the perfect woman"... I cannot explain the passion...he says he's never met a woman like me before.
I asked if he had ever been married before, he said yes and that he is technically still married however in the process of divorce.
He left Dubai yesterday and i stalked him on Facebook (we aren't friends on it)
I found this woman who commented saying "My handsome man" - in Spanish.
I clicked her page and her profile picture was of her and him in November 2013....
A friend of hers commented saying "You look amazing, can't believe you just had a baby".
WHAT. THE. HELL!!!!
This guy is taking me to Singapore with him in April and he's visiting my hometown London with me next week....
WHAT DO I DO?!?!
I haven't told him i found him on Facebook....
I feel so stupid for falling for him........

It's the 21st Century... sleeping with someone on the 3rd date is quite the norm.