While evidence isn't conclusive, better safe than sorry. If you are on hormonal birth control and need to take antibiotics, use a secondary method of protection (such as condoms while taking antibiotics.
Knife play? Doesn't sound very legal
I like to sucking your sweet pussy plz
If by 'dangerous you're referring to the spread of STI's, more dangerous than vaginal sex because the anus is not self cleansing the way the vagina is. If by 'dangerous you mean in terms of impregnation. very safe. I think it may also increase chances of UTIs in the penetrative partner, if the means of penetration is a penis.
Love how she exists to please her man.
Actually if your girlfriend/partner or whoever takes birth control pills, and you use the pull out method, it's like having a non existent condom, the chances of her getting pregnant are so minuscule that it's ridiculous. You'd have a hire chance of a Trojan condom breaking 5 seconds in and lord knows that simply doesn't happen.