Curate, connect, and discover
In cannon Reyna has never been anyone's first choice.
Jason was her fellow Praetor and friend, but he left her for new friends and a partner who he had fake memories with.
Percy then became Praetor and began helping Reyna only for the Argo2 to show up and him to immediately leave.
Hell, she wasn't even her sister's first choice as Hylla left her to join the amazons.
So, if she ever had a partner I feel that she would be shocked at the amount of care she would get, and she would be confused bc no one's cared for her before, and she would just adore being cared for.
I say therefore Reyna isn't cold hearted but has a bleeding heart, but is used to everyone leaving so she hides it.