Proposal got rejected with full relationship bars?

Hi! Signed in for the first time in forever just to jump in on this 2-year-old post. Reason, to thank Zackbrad cause I hope your theory is right. Have been playing by jumping between households (tried Legacy so much but just can't stay with the game when I do) and kept bumping into this problem. Was going nuts trying to figure out why the proposal rejection felt so random, with multiple couples whether in the same or different households. Going to test the "Going Steady" jump to "Proposal" awkwardness theory. (Side note: if there are exceptions to "socially acceptable" behavior in real life, should totally have that exception in a simulation! That's just a rant though)

Hope this works cause my main focus is on one familial line (so semi Legacy Challenge?) and never really want to put in hours on these side relationships. Only reason for focusing on them is to grow the neighborhood without a MOD. Will report soon :-)