The proximal end of the clavicle is closer to the
scapula or sternum possibly? ?

Sternum

Explanation:

Proximal end is also called the medial end

It means "close to the centre of the body"

The clavicle ,which is the collar bone joins medially to the sternum ,which is the breast  bone through a joint called the sternoclavicular joint.

The scapula is the shoulder blade and it joins with clavicle laterally.

if your boyfriend is cheating on you, my best advice to you is to dump him, he's only going to drag you down. and if you do, don't fret there's plenty better that know how to treat a person right. i mean honestly, the whole point of a romantic relationship is love, and if you love someone you aren't going to cheat on them. i do believe in second chances, but why would he cheat in the first place? i personally feel that if someone cheats, they ruin any chance they wanted/had with you. i wish you the best of luck with this, hang in there.