Someone help me out *long post*!

Okay so I want to run my current situation past you all, I’m 21 and have been with my SO for over 2 years. In December of 2017 we caught my stepfather cheating on my mum, after all shit hit the fan she took him back and as a result I couldn’t live at home anymore.

I was going to be okay, I’d always been fairly independent and money smart so I had options, but my MIL opened her house to me and my SO urged me to take up her offer. I’m more than great-full for her generosity and have done my fair share of the chores and helping out.

My MIL has a very open relationship with my SO and my SIL, this is something that I’m not used to and haven’t really been exposed too, I have done my best to adapt to this and have only ever voiced being uncomfortable when she has asked me straight up if I was pregnant or when she asks when my period is due - which I thought was fair.

At the beginning I was weird about her doing my washing as I have done my own for the past 5 years, I offered to do my SO’s and my washing myself, however she told me not to be stupid. So I adapted and help with the washing on a Saturday while I’m not at work.

Recently it has come to my attention that she has been taking photos of my underwear and sending them to my boyfriend and complaining about how I take my pants and underwear off in one motion... this is something I’m EXTREMELY uncomfortable with and not to mention embarrassed... it’s at the point where I am hiding them in a plastic bag in the boot of my car and am buying new ones until me an my SO move out next week..

There has been 2 times where she has taken the photos and sent them, and I don’t if I should say something or just wait it out ...

My boyfriend also hasn’t told me about these messages I came across them when using his phone ... he also doesn’t know I know and says his mum has no problem with me..

Can you ladies tell me how I should deal with the situation, I’m actually at a loss😅