I call a FA and explain as non-confrontationally as possible that all three of us are in discomfort and at some degree of risk in the event of an emergency requiring evacuation, after all that's the line they use when they tell us SLF that we can't have anything on the floor in front of us.
Apart from being a good line to affect a seat change, it is also a chilling reality. Your egress would be seriously inhibited if not impossible. What liability would the airline if that situation occured and could be proved.
Mind you, the way that we SLF are packed into aircraft these days, I cannot beleive that any evacuation could be effected in a timely or orderly fashion, despite the so called required standards.
Just to lever oneself out a seat these days requires a practised skill.