Be secure and trust her, you'll have no problem.
My boyfriend and I are really honest about all of that, he has no problem telling me how cute girls are around, in bars or at a party. I think it's normal to be attracted to poeple, I rather have a guy who can tell me honestly. I often tell him: "wow, that waitress is very good looking" and he'll look over and tell me what he thinks! That doesn't mean he'll go over and start flirting.
Anyways, what i'm trying to say, is that in the end YOU have the girl! She comes home every night and if you don't start thinking too much you'll keep her around for a while.
