I know that I am very straightforward and blunt with someone when asked to be. If an opinion isn't requested, I rarely give it.
In general, I'm very sarcastic, have a hard time complimenting people, joke around alot... The people I get along with best are the ones that understand sarcasm..and will bounce sarcasm back at me. Cause then we get into a lovely, meaningless word battle that is downright hilarious.
I pretty much treat people really close to me the same way...although I do have a tendency to offer opinions more often around people I'm used to being around. But I rarely share my 'feelings' with anyone. It's awkward and uncomfortable so I avoid it like the plague.