Eve is absolutely the type to be kinda submissive towards a guy and lay down and let them do what they want if she likes them enough. It's happened at least a few times in the series and she's short enough that it's easy to let happen. Will also canonically gave her the best orgasm she had in the series. Will would probably give head to Eve if he knew it would make her happy, especially towards the end of the series and probably in the post-series arcs after he worked on himself.
Also, Eve got head (at least) once in the series from an ex, so I could easily imagine her wanting her partner to give her some.