How much are you willing to tolerate for love?

I see so many people that put up with so much from their s/o, because they love them.

For example; Being in touch with an ex, lying, cheating, beating.
I think I could put with some of it but would probably draw the line at beating, although I have been in a relationship like that before, I wouldn’t again.

What you put up with? Where do you draw the line?