Swimming seems fast enough at start.. then you can masturbate in the shower, that will give you also the option to raise your willpower if you hold on your orgasm.. just keep an eye to the time and choose when do it, there're many chance someone will steal something from your closet if you do that in daytime
There's the cheat option to increase the rate of the relationship, will help also to get "faster" their names (yes will still take some interactions to get it also al x3)