can't help but do
cannot help but
A phrase used when one feels very strongly compelled to do something. We cannot help but intervene here, before you throw your life away on drugs! My mom can't help but meddle in my love life, even though I'm 30 years old!
can't help but (do something)
1. To have a compulsion to do something that is too strong to ignore or avoid. I can't help but lend my assistance to those in need. It's just who I am, I guess. After seeing you become more and more consumed by your addiction, we couldn't help but intervene.
2. To have no control over or be unable to avoid some action. I know you're irritated, but our guests can't help but arrive late if they're still stuck in traffic. I know it's silly, but I can't help but feel like I failed you somehow.
can't help but do something
[to be] unable to choose any but one course of action. (Also with cannot.) Her parents live nearby, so she can't help but go there on holidays. Bob is a tennis fan and can't help but travel to Wimbledon each year.