For those of you who don't know, the sexual acts that take place have a reason why I chose them beyond simply looking hot. Please ignore the strange colors, it is a result of the gif converter.
The hand job, while it is often depicted in hentai as an amazing experience, the reality is that if feels exactly like fapping yourself, except far more awkward. If a girl is giving you a handjob it is general out of pity, she doesn't want to blue ball you, but at the same time she doesn't want to do anything truly intimate with you. It is the bare minimum.
Next in line is the boob job, while gloified in hentai, it you look at the mechanics it is basically just handjob with tits. She might want to try taking things further, but she isn't sure and so she settles on something that is sort of erotic but not really dangerous. If a girl is interested she might give you a boob job but she hasn't really made up her mind.
A foodjob is not a sexual act among equals, it is basically telling the person "I can crush your nuts whenever I want" and is an unapologetic power move meant to estalish the woman as the dominant sexual partner in the relationship.
Missionary is an indication that she want to have sex but she isn't really seeking anything crazy. It shows the intimacy of two sexual partners without involving anything really kinky. The "default" setting of sex.
Blowjob is on step up from that, it is proof that you actually turn her on and she is ready to experience more kinky things simply because she would rather turn you on than simply make babies. While this is the turning point, it shows that the woman seeks pleasure and excitement from the man rather than going through the motions.
Doggy style is an unapologetic male power move. While is is arguably more pleasurable for the women, and implies that your cock feels so good she'll let you fuck her like an animal just because you are so dominant of a male.
Cowgirl is the reverse of that, but implies a similiar thing, so is so hungry for dick that she will fuck you whether you want her to or not. Unfortunately the animation is messed up and his hands hover above the girl's legs no matter what I do. So there really isn't a good way to make it look natural.
Then you have girl-on-girl action, for most things it needs to be custom animated, but it is mostly a show of submission towards the cuckcake.