What does he plan on doing? He plans on unlocking the 'golden stiff finger'. Remember, he hadn't unlocked this skill yet, he doesn't even know what using it would feel like.
He was in a situation now where this skill would be of great use. Yes, soft moans were escaping Lucia's mouth, she was feeling little pleasure passing around her body...and that's 'cause he increased the pace at which he was fingering her pussy.
He wanted the pleasure passing around her body to increase, he wanted the moans escaping her mouth to become more audible...he wanted to give her proper satisfaction.
He wanted her to feel like, 'Wow! This guy is really good at fingering pussies'.
So he was still fingering her pussy with his normal finger when he called out on the system from the mind,
'System'.
<Yes, host>
'I want to unlock the golden stiff finger'.
<Are you sure you want to unlock this skill?>
'Yes'.