I want to find this book, although, I don't even know how the cover is and actually someone else was asking for title on Goodreads, but since nobody knew, and by that time I just really needed to know even when I've never heard about it, until her request. So this is what the girl wrote about the book I'm just copying/pasting her post.

I NEED TO FIND THIS BOOK!!
He's a wealthy club owner, she and friends went to his club, they had an argument, their paths kept crossing due to mutual friends, they became f*ck buddies and she leaves him due to another woman, he finds her again, and she is pregnant, she tells him its not his... Any clue ?

I don't know if it's the same book but I read one with similar plot a long time ago
"SOLO" by Jill mansel.
Hope you find what you are looking for.

I added as my friend to the girl who asked for the book first, and I asked her and she said that it wasn't. But thank you, you are the first and only who came with a book title, and I'm going to read it, the plot seems similar, and I guess is fairly common (that type of plot) and it's going to be hard to find it, anyway, thank you so much!

No problem