When I gave Lust potion to Rhot, it was 7 in total.
Can't raise Lust anymore?
Warriors Lust and Acolyte Lust is only gained from event and quests. There's an acolyte around ruins that you can give lust potion, you can give Lust potion to Rhot when you are talking with him. You can offer relief to warriors and it also gives some points. A lot of points can be gain when doing Lost Acolyte quest and picking the lusty options.