Hi Gareth,
I've often read about the lack of PDA, and have felt very hurt by it myself.
Most of the time, it proved to be a major signal of a man's ambivalence toward being exclusive, committed, a couple, The Man in My Life.
Private affection is lovely, but sometimes that's about sex, not commitment.
I feel that if a man really loves me, he will be connected to me in public. I don't need sidewalk necking, but likewise I don't need to feel I've slammed into a refrigerator when I send a signal in public that I'd like to be acknowledged.
I remember yearning for him simply to put an arm around me. To introduce me WITH his arm around me and a warm glance my way.
To feel, when we're out together, that we're together. For him to not let go of the thread that binds us just because other people can see him. His great self-consciousness is off-putting, because it makes any outing all about his comfort zone, not about enjoying an experience together.
When a man maintains a very different boundary or sense of "space" around him when others can witness than he does in private, it now means to me that this man may be enjoying me, particularly in private, but he is not seriously weighing a future together.
If you can still have very focused one-on-one conversations with OTHER people (especially women) when you're out together, then if you care for her but feel avoidant or paranoid about any sign that you're With Her, perhaps you should have mercy on her and end it.
If she wants your full commitment and behaves as though she would give hers, but you have no clear answer from within yourself, you owe her honesty.
Being blunt since it's been a long day and since it strikes a nerve...I don't mean to offend you.
best,
Hopalong