I'm tired of my sister's boyfriend being here all the time. what to do?

my sister has been with this guy for like 6 months. and every since then, it seems like she is completely obsessed with him. he is here everday, from morning till night. it's like my sister just has to see him and its really annoying. I mean like seriously can't she just go a day without seeing him? not that I hate him but i'm just so tired of him being here all the time.. I would just like one freakin day when he isn't here. I would just like to have my house back and be able to watch tv and walk around in my pjs all day without him being here.. I have a boyfriend who i've been with for 3 years and I am not like that at all. I only see him about 3 times a week. I have told my mom how I feel but all she says is 'I know you feel that way, I am kinda tired of it too' but I don't think anything can be done and I don't know if she would tell my sister anything because she doesn't wanna hurt here feelings but yeahh he just practically lives here. any help on what to do?