Sometimes you can over-think these things. Is there a commonality to his breaking of boundaries? If you look at the situations surrounding them can you tighten up the boundary before it gets wobbly and is broken? My partner is hopeless at maintaining boundaries when sleepy so we tightened up the boundary so that he doesn't have sleepovers except with his secondary who is celibate anyway.
I don't think we are generally at war with our sense of loss and our ability to care for ourselves, even though it can seem that way. If our sense of loss is too profound then it is a sign that in really caring for ourself we are not ready for such a loss.