First time ever crossdressing was for my cousin

This this happened when I was very young. I remember my uncle and cousin used to live with us for a few years. 2 cousins, 1 male and female. Both were a couple of years apart, I would sleep in the same room with my male cousin but never slept close. One night I decided to sleep on the floor and he also joined me, the lights were off and then I started to hear this wet fapping noise, I moved my hand over to where my cousin was laying down and felt something wet. I quickly pulled my hand back and smelled my hand, it was an odor I did not know at the time, I did not think nothing of it and went to sleep. Next day I was playing with some of my toys and my cousin tells me he wants to play so he invited me to the room. I'm standing there and he tells me "let's play dress up" I said okay. He then pulls out my other cousins 'F' underwear and bra and tells me to put them on, so I thought it was cool and did. He started to touch my breast and then my ass, it felt pretty good feeling my skin with the satin undies. He asked me if I wanted to play boy and girl, I said okay so then he pulls down his pants and sits down. I'm giggling because I never seen him naked, i get closer to him and start to grab his pennis, start playing with his balls. I then get on my knees and slowly open my mouth and start licking the tip of his cock. I start licking the precum from his head, he then grabs my head and starts fucking my mouth fast, not deep pumps but just enough to have his head go in and out of mouth, he then stops and I feel his warm c start filling up my mouth, I remember gagging and wanting to vomit at first lol. But tried to keep it all in my mouth. I started dressing a little bit more after that.