Is it normal i love when my girlfriend does this?

I love it so much when my girlfriend sticks her foot in my mouth.
We do this later in the day after she’s been wearing her shoes all day. I’ll lie on my back, and she’ll take her shoes and socks off, and her feet are all sweaty and stinky.
Then I open my mouth and she shoves her moist bare foot in as far as it will go. When it’s in I like to suck it and lick it and taste the tangy sweat and it gives me an erection and I lick her big toe while she moves it around, and I don’t even gag because I’m enjoying it so much. I also like moving my tongue along the other toes like a little xylophone. God damn it makes me so horny, especially when she goes “mmmm” and giggles and says “oh yea.”
Anybody else do this?
Oh and it turns me on even more if she’s naked while doing it and I’m naked too, Or if she’s wearing only a bikini.