I'm writing this to vent as I'm feeling a lot of frustration, disappointment and disgust towards this person. Obviously I can't really express this because I don't want to hurt their feelings/having these feelings towards a trans person isn't really acceptable. To give a bit of backstory, this person would be best described as a family friend now, but before my parents met was married to my mother. He had/has plenty of mental issues - I don't want to get into much detail in case anyone who knows this person somehow reads this, but from what my mum has said he used to like dressing as a baby (using nappies, adult-sized baby-gros etc).

He also had a poor childhood, which my mother supposes is the reason he liked to regress to babyhood. This was before I was born so I was never actually exposed to it. He was present during much of my siblings and I's infancy, and when we were younger he was always very kind, gentle, and loving. Whenever me and my siblings would see him he would tell us stories of when we were babies and things that happened when we were too young to remember, which we loved. When I was a bit older, I remember him taking me to a park and pushing me on a swing. He told me that he believed I was actually his daughter (not my father's) as I looked like his sister. He said he could just walk off with me right now. Although this sounds alarming, at the time I was old enough to recognise that he wasn't all right in the head and I still saw him as harmless if that makes sense.

As to the way things are now, ~10 years later, he recently came out as trans and took on my older sister's name. He insists this has nothing to do with my sister and that he has reasons for liking the name before she was even born. It disturbed me and my sister that he chose that name; there's so many names he could have chosen?!. Every time he is around and I try to get my sister's attention my saying her name, he will repeatedly say "what?" until I clarify that I was talking to my sister. He will then say that he knew that I was trying to talk to her all along then giggle about it, for fucks sake. Although I call him this name to his face and use his preferred pronouns, I'm using 'he' throughout as I feel like I shouldn't have to hide my true feelings here. I feel so conflicted about the whole thing. On one hand, he seems much happier and more outgoing since beginning to present as a woman. However, he says really creepy/offensive things which piss me off, and he is so in your face about his transition. He sends me messages saying that medical tests have shown that he is 80% female. He says that since taking oestrogen his thoughts have changed, he is weaker and his bones are smaller. He claims has different ("feminine") hobbies. Basically just transforming himself into a caricature of what he believes is a woman.

He came on a shopping trip with me and my sisters. I was shopping for some new pairs of underwear and he stood next to me whilst I was trying to choose. He asked me what size I was then asked me to guess what size he was. He told me he was wearing size 12-13 girls underwear with unicorns on. It amazes me that 60 year old men can say they are wearing little girls underwear and because they are trans, they don't get labelled a pervert when they clearly should. We went to a dessert shop whilst on this shopping trip, too, and my sisters got crepes/waffles whilst he had a cappuccino. Whilst we were eating, he made comments about our weight and kept mentioning the calories in our food, over and over. He said he wouldn't eat anything like that because real girls have to watch their weight. I'm just so over this person. Everything that comes out of his mouth disgusts or angers me and yet society is firmly on his side. I don't want to speak to him or be around him.

I just don't understand where the person I used to know went. I feel like I should just give up on him.