I want to do anal with my girlfriend

It's pretty normal. Bring it up casually, see how comfortable she is with the idea, suggest it might be fun for both of you, see what she says. If she outright refuses, you'll probably have to give up any hope.

If she seems like she might be open to the idea (excuse the pun), make sure she knows: you'd be careful to use lots of lube, you'd go slowly, and you'd stop if she's in pain. Then leave it up to her to make the decision.

The main risks are pain for the receiver & 'mess' (along with the smell) - both often an instant mood-killer omitted from most mainstream porn. So be prepared for the guilt of hurting her ass, for having to wipe shit off your dick, and her mortifying embarrassment at her shit being on your dick along with the stains on the bed sheets. You may want to do it in the shower to be on the safe side, although be sure not to wash off the lube as you go.

As long as you both have your facts right about anal sex, you can both make an informed decision

It would behoove you to get some help on how to do it correctly, so it won't be too painful for her, before you even ask. If she is interested, and you go at it like a "bull in a china shop", you will ruin it for both of you.

Haven't you heard? The gentlemanly thing to do, if you want anal; Buy her a strap-on dildo for Valentine's Day. Then you offer to "go first" ! (meaning, take the receiving role first)

Ok I'll be honest, this question is out-of-bounds for me to answer, because I have a strange aversion to anything that has to do with butts. Sorry for posting here, I couldn't help myself... However, other people are into that, so your girlfriend could be, too. I only have ideas- like you could curiously strike up a conversation with her, one day- ask her if there's any adventurous sexual fantasies that she's always wanted to try. Then see if you can work your way into telling her your own. Try to fulfill whatever fantasy she has, in exchange. Though, if she tells you she's not into anal- then you may have to accept that's how she is.

Sadly this repulsive habit is becoming normal in the USA. I doubt if it's done anywhere else

Ask her if she has any kinks/fetishes.

i mean you could just "accidentally" stick it in the wrong hole and see how it goes from there

i dont recommend that just a suggestion

Just talk to her about it, maybe even during sex. She may be more open to the idea when turned on. In my experience women need to be really turned on to want it.

You go and buy a strap-on dildo. Then ask her to stick it in your asshole. Do it a few times while moaning and groaning like an idiot. After that, she should be excited to try with your dick. Done!