Need some advice on a situation I never thought I'd be in.

I'm 29, married no kids, and I have a sister who's 24, single. Dad is 60. Mom passed away from cancer last year, January.

After mom passed, dad dated for a while, but ultimately decided he wanted a new wife with a different cultural background "because she'll be more docile"---his words, not mine.

Dad sold our family home and belongings and left the country in July. My sister had been struggling to complete school and find work, so she was still living at home. When dad left, she was kicked out and has had a rough time financially since. I help out where I can.

Dad kept us updated on his dating. In December, he met someone who was docile enough for his liking. 6 days later, sis and I both got a text that he had proposed and they were engaged, with plans to marry ASAP.

We were concerned about the speed of things, so we asked for the opportunity to meet our step-mother-to-be before the wedding, hoping it would slow things down a little and giving the two of them time to actually get to know each other. You see, dad was emotionally abusive when we were children. Mom suffered severe depression and we suspected that he preyed on that. His antics continue to this day. We secretly wanted the woman to have a fair chance to figure that out and decide if I was the life she really wanted. Unfortunately, we weren't able to reach out to her directly.

Dad refused to delay things or let us meet her, but did send us pictures and details. The woman is 15 years younger than him, absolutely stunning, and runs a beauty/fashion business through social media.

They were married in March this year. Dad transferred all the money from his bank accounts---everything from our family home and investments---and from the pictures he posts they've been living the high life off it. For now. Dad is terrible with money and likes nice things, and apparently she does too, so they're burning through everything.

They've made plans to come visit me this summer and have started making demands (both of them) about things they want from me. I don't even know the woman and dad is like a stranger now.

The cherry on top is that she has a son, 22, from a previous marriage, and has designs on using me (I work big tech) to land him a high profile job. Apparently dad told her I could.

I'm struggling to wrap my head around the whirlwind of events. I suspect it's all dad's way of dealing with grief over mom. He says he's past it, but a year isn't much when talking about grief over the death of a wife.

How do I respond? Do I smile and embrace the madness? Do I put my foot down and separate myself from the only family I have left?

Do I help them out (finances, housing, connections) because they're family? Do I refuse because I, frankly, don't trust either of them?

Help.