How to tell if you are about to be dumped

1 Conversations behind closed doors

You hear the dull murmur of conversation night after night when she closes herself off in some remote corner of the house, but she never mentions the calls, or who she's speaking to. I hate to break it to you but most of those calls are to somebody new, and the ones that aren't are those in which she's discussing (probably with her Mom or best friend) how to dispose of you mercifully. 

2 A social scene that you're not part of

"We're just going to talk about work… you wouldn't like it." Sure, that's probably true some of the time, but when it becomes a regular habit something else is afoot. New friends are ripe with new possibilities and can cause the mundane (that's you pal) to seem limiting and regressive. Soon it will be time to make some new friends of your own, especially if she takes your entire social circle with her in the split. 

3 The delay tactics

"There's something we should talk about once you finish this semester/business trip/prison sentence." OK, if you really are in prison then I'm going to go ahead and side with her, but otherwise this is the classic warning shot across the bow. She's mustering her courage and/or transferring her savings into a non-joint account. 

4 The unexpected domestic circumstance

"My sister/mom/Pilates instructor is going through a really difficult patch, so I'm going to be staying over there for a while." She's looking for space and time away from you, and it's just easier to obscure the true nature of the situation. You might disregard this sign if the person in question has a history of drama — this could be a legitimate situation and the best you can do is to read her body language. Does it seem like she's going to miss you? If not, you've been warned. 

5 All of a sudden it's casual

If she starts introducing you as her friend it's probably all over, unless that's just how she rolls. If she's not the sort of person who changed her Facebook status the week after you met, which is probably for the best, then that leaves a certain amount of grey area out there in the public sphere. Some people will take advantage of this when it suits them, but here's the good news; she's probably an undiagnosed sociopath anyway.