Fiancee staying out for days partying

Hi, my fiancee and I have been together nearly 10 years and when we got together she was a bit of a party animal but did calm down a bit but the last few months she has gone back to her old ways and every few weeks she goes out and doesn't come back for days, she also makes no contact during this time not even answering texts.Twice in the last month she has gone out on the Friday night and not come home till Sunday night, at the moment she went out on Saturday morning and is still not back and it's Monday morning.I am getting really sick of this now and don't know what to do as we just bought a house together last year.

You've been together nigh-on 10 years but for how many years have the pair of you been engaged? That detail, including the ins and outs of her bad conduct, aside, here's an acid truth: if a person was Red when you met them, then developed more into a shade of Purple for a while, but subsequently (whether or not based on any discernible trigger) changed back into Red, then Purple was never the default colour, was it. Red was/is. Which means Purple was a contrivance. Which means you proposed to a more or less pretend persona, didn't you? Has she all this time been a great actress or have you been blinkering yourself? Whatever/whichever, I'm sat her finding it incredible that your fianc-FIANCEE!!! goes completely AWOL and (despite modern technology making it p*ss-simple) incommunicado for da-DAYS!!!! at a time, which she's been doing for mont-MONTH-UH-SUH!!! and yet you haven't dumped her yet! FYI, I've just read out where I've got to on your thread to Mr Soulmate and, without missing a beat, he yelled this: "JEEEEESUS!!!" Are we the barmy ones or are you? :-o Oh, wait... the house purchase.... Okay... Not barmy, then. It looks very much to me like she suddenly feels far SAFER than she ever did when it comes to revealing her true colours, now that (as she sees it) you're effectively trapped into putting up with her sh*t and nonsense, this highly anti-fiancee behaviour (in fact, anti-relationship behaviour!) - by this enormous, mutual business investment. Well, more fool her. Because, on the practical front, all you have to do is end the relationship so that either she has to buy you out or find someone else to, or you her. A third alternative is that you end the personal relationship but (through keeping it amicable/civil) retain the business one and, instead of living in it, rent out the house so that you not only retain the investment but also meantime make a continual monthly income out of it. On the romantic front, her 'feet' are saying EITHER [a] "we want to be single (I hope he fires me)" or [b] "we want to get to behave like we're single as well as get the perks of marriage-in-motion" or [c] "we're cheating and not even bothering to hide it very well" - all three suffixed by, "...considering we've got him by the wallet-y short and curlies". One, two, three [altogether now], 'Ugh, don't fancy yours much!' Poor you. :-( So what are you going to do?