Han only saw the names on her wrist once, and once was all he needed. She was happily eating anything Maz set before them, her gloves removed and set aside giving Han a clear view of the names on them. On one wrist was 'Ben Solo' on the other, 'Kylo Ren'.
His gut clenched as he observed Rey, oblivious to the destiny that lay in her future.
Despite not being Force sensitive, Han sure had a knack for getting involved in those matters.
Still, he couldn't help but be relieved. Rey would either be his son's death, or his salvation.
Inspired by that soulmate AU post in the obikin tag on tumblr, where one wrist has your soulmate's name and the other has your worst enemy's and you don't know which is which.