The love language that Eric, Elena and Jess all ranked at the top was Quality Time.
The love languages are first and foremost about how a person likes to RECEIVE signs of being appreciated and loved.
So, it was especially key that Eric and Elena both said — and did — spend time with Jess, just getting to know her. This made her feel valued and appreciated, even as much as she was agreeable to the sex between them.
Jess’s need for Quality Time as a sign of love is rooted firmly in her past, not feeling appreciated by anyone enough for them to stick around and just get to know her. She’s been in foster care and lived a transient life.
Quality Time rose to the top of Eric and Elena’s lists because the other choices mattered less when it came to a choice between that or a thing (“Receiving Gifts”). Quality Time preferred over having someone do something for them (“Acts of Service”).
Eric would love Elena (or Jess) just laying down with him when he’s tired instead of doing his errand or chore for him. Elena, too, would much rather spend time talking or watching a movie with her partner than having them do something for her.