then again i'd think a computer is a big purchase and that he should have mentioned it to you. you mention though that you've been separated several times, maybe he thinks of it as something not on a need-to-know basis?
Talk to him about it. An honest conversation in which your expectations are made clear, and he understands and empathizes is the better outcome. If you're met with anger, annoyance or defensiveness, then you will know that you're dealing with wayward behavior and you can make your decisions from there.
To then turn around and buy a computer for someone after making such a grand statement smacks of intentional misleading.
It may not be a dealbreaker, but I'd have my ears perked and eyes peeled at this point. I'd be interested to hear how he responds to your knowledge of the purchase.
It almost seems as if your WH is continuing to live 2 lives. The life that he wants with you.....and then that other life that he'll have if you 2 don't work out.
I'm with Jrazz on this one. It's *ok fine* for him to tell you emphatically that he's not going to buy her a computer.....but he most definitely should have given you a heads-up about his change-of-mind.
Plus...you said *our* finances. So you just paid for 1/2 of missfriend's new computer. Without your knowledge or permission. Not.Cool.
In my effort to be *concise*, I often come off as blunt and harsh. Sorry, don't mean to be offensive.
Keep your eyes open. Good luck with the confrontation & let us know what happens.