Don't stretch the progress with Ashley she isn't the main "love" interest of the protagonist. Leslie should be the last "f****y" member he fucks not Ashley. Hopefully you will advance her sexual progress further and faster in the next update with 4 new quests in which you start with like hotdogging/rubbing on her ass and progress it to blowjob in the final quest with a handjob and titjob in- between. It is always best to save the most taboo for last. Wanting to boink your S ain't that taboo lately with more porn focusing on that and the fact that there is no real power dynamic difference since the ages are similar. Not to mention cases of i****t involving b/s are the most common type by a lot. Most games(90%) have you progress faster with the sister than with the mother. And those are the type that are the hottest and most memorable.
Keep up the good work you are the best <3