Don't go dutch
If you don't pay for her, she won't be going out with you again. She probably wouldn't even bring money to your date, unless she's afraid of having to make a quick emergency exit out the back and pay for a taxi home...
Don't burp in public
Bodily functions are a big no-no. Everyone on the bus will look at you like you are an axe-murderer and you've been killing puppies in front of them. And for god's sake don't apologize, it's like raising your hand and telling the judge, "Yes sir I am very guilty." So don't apologize, just let everyone ignore it and look terrified.
Don't take the last shirt
Russians will literally offer you their earthly possessions if you comment on them positively, this does not mean you should take them, they are just trying to be nice.
Don't joke about the parents
Russians literally don't care about any other kind of joke, whether it be racial stereotypes or puns. But don't joke about the RENTS! No one will understand you, they don't make your mom jokes.