I am looking for advice on how to handle this situation with my SM. I'll be straight up; I find her sneaky, manipulative, spiteful, underhand and selfish. So, I may be coming from a biased place . I don't know where to start. Her and my DF got together about 5 years ago, and from the beginning I was really pleased he'd found someone and felt very keen and ready to welcome her into our family. However, it soon become apparent that she did not see things the same way. We went on a big family holiday the first year, and on one of the nights, her, my Dad and her kid and their DP all emerged onto their balconies, while me and DB sat flumoxed, and they all went off to dinner. I was in my 20s at the time, and hurt beyond belief. Earlier that year she had 'joined' my Dad on a trip we had planned abroad. I was moving from one part of a foreign country to another, it was all planned that we would drive from one part of the country to another. It had been planned before they got together, but she came along and then insisted that we move everything a day earlier, so she could get back in time for work. This wasn't possible as I was going to stay with a friend for some weeks, and had already arranged a date that couldn't be changed to arrive. I got the sense that she wanted to assert her power and demonstrate that things fitted round her (I'm not a paranoid person at all; it was odd and she invited herself on the trip and then tried to change all the arrangements to fit with her). She has become close with my grandmother, and out of nowhere, my grandmother is suddenly very rude to me whenever we speak. I don't have much wider family and to me it is devastating. My father talks sometimes about her controlling behaviour and suggests he wants to end things. I am broadly supportive of their relationship, but find it upsetting as she tries to prevent us spending time together one on one. He has confided, after some years, that she is jealous and insecure. WWYD?