I got it at the literal last second.
There are three bonuses you want to look out for: frosted cookie bonus, air bonus, and pull out bonus.
Pull out bonus can be acquired by pressing E right as the bar fills up completely.
Cookie Bonus can be obtained by pulling out and cumming on the cookies. This can only be obtained once per attempt.
Aerial Bonus can be obtained by jumping right before you cum. This can be a little hard to obtain because masturbating and jumping are both set to space. You need to pull out once the bar gets to the ending circle, mash jump, then use E to put it back on. At least, that's my method to doing it, but this is definitely the hardest bonus to obtain.