+1 i have the same with my current gf of 2.5 years. she asks for my help daily, stuff like massaging, help with homework or to bring her stuff and i sometimes even do it, especially when she has a stressed day but i say a lot of times no too.
this way i look dominant but not too much of an asshole cuz only girls with low self esteem and daddy issues want a complete asshole who cheats etc.