Hmm, I could see both of them being either. That convo where they were discussing their past sexual experiences was pretty enlightening and if we were to follow it to its logical conclusion, Val never caring much for the sex she had with her boyfriends and Juls never being interested enough in anyone at all until Val, it’d probably be gay for both of them.
Buuut, I think that might be more…you know in these beginner stories, they kind of don’t even acknowledge bi as a thing? The writers could be working from that mindset. OR, also pretty typical, to sell the whole soulmate aspect, they weren’t particularly interested in anyone until they met each other. The show’s brought up the whole “are we gay?” and “with a woman?” thing enough that it is still about a sexual identity, even if both are ever only truly in love with each other on screen.