My Girlfriend Sits On My Face All The Time!

Let me start off by saying that ever since I was a little kid and played super heros and stuff like that I would always imagine the evil person to be a girl and she would try and sit on my face and having two different video games where girls do that didn't really makethi gs better. So a couple years ago I got a wonderful girlfriend let's just say were 18 now but after about one year of dating she would sometimes sit on my face and fart and because I like it I didn't stop her I just acted like I hated it and then for a long time she stopped doing it the only time she would do it is when we would wrestle sometimes. But only a couple months ago she would start to do it bit she would pull her pants down and acting like I didn't want her to I would beg her not to which would make her more eager to do it and now she doesn't even have to fart she will just sit up there thinking I hate it she will spread her butt cheeks and make my face go right in her butt crack. She'll say stuff under her breath and make gestures about it when were out with friends, and just a little while ago I find out it actually turns her on( I sorta already sensed that cause she want to have sex really bad a lot of times afterwards. Now its to the point where she'll take pics and videos on my phone of her doing it one even where she made me take the video so she could spread her butt cheeks apart and make me kiss, lick, and even stick my tongue up her butthole. If she knows she's going to see me she'll sometimes not take a shower just to make it smell worse and almost everytimes after she takes a crap she'll sit onto face and even with me loving every minute of it I can't deny how awful it smells. She's gotten so into it that she's started shaking her butt and my nose started slip up her butthole and when she got up she started laughing hysterically cause there was some toilet paper stuck on my face. I sometimes play around with her calling her a little ***** saying I dominate just to get her to do it. I'm now being threatened that she'll sit up there and watch her TV shows and I really hope she does!