Okay, and without being catty - from what I know, actors love their jobs and some justify the amounts they are paid by saying that they would work for nothing (don't tell their agents!) and what they are paid for is 'the other stuff'; the disruption to their lives of the constant travel for location work, the time they are away from their friends and family (and garden!) the intrusion into their personal lives by paps, photogs. and everyone else, etc.
I think Sean has been around long enough to accept how things are, and given that there are so many photographs with fans and such positive interactions reported with him, he is obviously someone who deals well with the blurring of the edges of his personal and professional life. Likewise, if you are involved with someone in Sean's' position, those rules apply to you too. You may not feel so happy about so much female attention but it doesn't seem to bother him - oh no baby! - and you may not like that his meal might get cold because he is signing autographs, or he takes ages for a cigarette break because people will approach him when he is having one outside and so there will be more autographs and photos. and so on, but that is his life and his rules are what you live by, with grace, whether you feel it or not!
Those moments are, for the fan experiencing them, huge. It is their once-in-a-lifetime opportunity to talk to someone they admire. Some are too overwhelmed or shy to approach until someone else does, it's a big deal, but it is that one moment for them, something that may never happen again and it is really, really important that the focus is them for that time. Okay, so each of those moments may happen several times a day if you are approachable for that, but in each of those moments, 'the other half' has to remember that the fan is all that matters; and that meeting is something they will remember and be telling all their friends about for ever possibly so the g/f, b/f whatever ' is completely un-important, should know that and behave accordingly.
Some people will not even be fans, they simply see someone vaguely familiar, or someone signing autographs and doing photos who must be famous so 'we'll get in on the act' but again, they get treated with respect, and the g/f or b/f, wife, husband, deals with it, with some dignity, not pushing in, just there to take extra photos on people's 'phones when needed, to hand over the extra Sharpie and above all, knowing their place - this is not anything to do with them, it is about the celeb. and the person they are talking to, and I don't see that going on here; maybe she is just too young to know how things should be done.