Can normal girl guy friends travel together?

Anonymous
So I'm seeing this girl, and we've known each other for 5 or so months. Things are going well when we see each other or go out, but we're not in a committed relationship yet.

We spend most weekends together; however, there are weekends where she goes traveling with her guy-travel buddy who she knew back in HS (10 years ago), so definately much more than I know her. This bothers me I and don't think she's ready for a serious relationship. So my questions are:

1) Am I reading into too much, and can normal friends of opposite genre travel together?

2) I really like this girl, but am getting weird vibes due to this traveling biz, what can I do?
Can normal girl guy friends travel together?
2 Opinion