So let's say that Newt has one last night before his ship leaves and spends it in the Goldstein sisters' flat. And it's been a long few days. He's so tired. He's feeling guilty as hell over being unable to save Credence, he misses Frank already, he misses Jacob who was one of the first real friends he'd made in who knows how long... basically he ends up crying himself to sleep and it's not any better once he does, because he starts having nightmares about Credence's death and being tortured by Grindelwald and losing his creatures and all the terrible things that could have happened, or did happen.

Tina's already asleep but Queenie senses his distress from the other room and goes in to comfort him, basically just hugging him and sympathizing and letting him cry it out. Newt is used to facing nights like this on his own, and doesn't always find it easy to express his feelings to other humans, so it's a huge relief to have someone there who cares about him and can understand what he's going through without him having to explain it. It's also 100% platonic, no sexual or romantic overtones.