I've always been affectionate with my cousins, but my younger cousin is acting weird

I'm 21f and my family is really close to our cousins (23m 17m 16m and 6f), when i was about 9 I met them when i came to live with my mom, and I've always hugged them and have been physically affectionate. my mom and older sister didn't like affection and i didn't have many friends so i did go over board when i saw them- i started learning boundaries with them after a few years, so by 12 i calmed down a lot.

When i was 14, my friends smoked weed and i didn't understand how to do it, so my older cousin showed me during a sleep over and he took my affection as romantic. i was too scared to say anything, but next time they came over to my house i was asleep and laying on my stomach, i woke up to him leaving my room and my clothing not how i wear it, since then i try to avoid him as much as possible.

I moved out at 17 and used to visit every birthday, i was still affectionate with the younger ones, lots of hugs to the boys, affectionate words, and with the girl i always carry her and snuggle her and kiss her hair. I just moved back like a month ago and we've been going on trips, the first trip with my family and the two youngest, me and the two youngest sharing a bed, the second one just me and the youngest boy (to go to a concert) with separate beds, the concert was very packed so we were very, very close together.

The last overnight trip though, the first night the older cousin kept trying to get me to smoke with him and even woke me up in the middle of the night trying to get in bed with me but i pretended to just go back to sleep and shoo him away. The younger cousin and I sat next to each other on the couch and we were snuggling a little bit, arms touching and resting our heads on each other, he wanted to cuddle more, like put his arm around me, i redirected by repositioning and checking on the younger kids playing so at the end he took a nap laying on my shoulder. We drove back really late at got to dropping his family off at about 12.30, and since i was driving i forgot to tell my mom to leave the door unlocked and had to stay the night.

The options were living room, right outside where my older cousin was gonna be, or the younger cousins room. i choose to sleep in my little cousins room, i brought in another blanket so he was under the comforter and i was over it, he wanted to snuggle so i put my arm over him and he was a bit closer, i thought he was too close to my face so i moved up onto the pillow more and as i was falling asleep i think he might've kissed my neck. I don't want to stop giving him affection- it would single him out as i give the 17y/o hugs, i like to carry him, and take lots of pictures, and the younger girl always wants to hangout, play with us, and I'm constantly giving her affection and attention.

I won't be sleeping in the same bed as him again without other people in the room/bed (how it is for trips) and i already do well to not kiss the boys anywhere or hint at it, I've also made it clear that i see them more like siblings. I also stay sober when I'm with any boys so the incident with the older one can't repeat itself. but his family is worried about him being inside/on his computer all day so they've been pushing me to hangout with him more and be a positive influence. how else can i go about this?