I just really don't think there's a whole lot else to discuss... I'm sorry, but I think it's best to just let this be as it is... You told him what you wanted and his wants differ from yours and that's totally okay but I think he doesn't need anymore explanation, but hearing more will only hurt him more. He knows you want to be poly and he doesn't so he did the best thing for both of you by saying goodbye. He doesn't need to stay with you and hurt himself by letting you do what you want and he doesn't want to trap you by staying with you and not letting you do what you want. Let it be goodbye and go your separate ways, I'm sure it hurts but it's for the best.

If you want to be friends, give him a few days and space to work through his own emotions, if he has any questions I'm sure he'll ask.

I understand what you're saying.

I think cuddling and clingy are interesting terms to use when it comes to family though.

The important question is, what are you comfortable with? If you want to maintain that closeness with your sister, set that boundary with your girlfriend, ask if there's something you can do to help her be more comfortable with how close you are to your sister.

If you'd like to perhaps distance yourself from the cuddly/clinginess of your sister, you need to set that boundary with her and make it about you, not your girlfriend.

If your sister reacts poorly to that, that's her own issue and you would then need to sit down and have discussion with her about her inappropriate behavioural reaction to you trying to set boundaries with her.

Being able to set boundaries with people is important so while its hard it is good experience and a skill to work on no matter who it is you end up setting boundaries with, stick up for yourself and voice your opinions, what you want matters.

I, 24f would cuddle my mom the same way I'd cuddle my female best friend. Platonic affection is not inappropriate or weird. I would never in a million years cuddle with my brother but honestly, I don't talk to him either because we've never had a good relationship. I'd cuddle my step mother but not my father, I think that'd be weird and I have a great relationship my father. I'd cry to my dad, and I'll vent to him and he vents to me, we all watch movies together and spend quality time together but I'd find it weird to cuddle, yaknow? If I were you I'd ask her why she found it weird and where her boundaries with that lie. It's okay to set new boundaries as long as you are also comfortable and okay with the agreed upon boundaries.

She doesn't owe you a hello.

You broke up with her because of your mental health and started seeing someone right after the breakup.

You mentioned her being a bit controlling about female friends and then go on to say that you broke up a few times and got back together but not the last time because you started seeing a female friend right after the break up....

If this happened to me, I'd feel really betrayed and pissed off.

Don't expect anything from her and don't text her. You can reminisce but if she doesn't want anything to do with you, leave her alone.