my bf (who is in the forces) doesnt cope well if i am feeling a bit down or emotional either. it makes him 'nervous' like he is worried its about him or i am going to leave him or start a fight or something - he hates discussing this sort of thing totally. but...i hope this reassures you to know that if we are having a bad day, or we are in a mood, we arent 'purposely acting in a mood' its just that we are in one. When girls are in a mood its usually because we are unhappy about something but its difficult for us sometimes to express what we are unhappy about so we clam up and say stuff like 'i'm fine' when its apparent that we arent fine at all...you know what i mean.
Sometimes its PMT and we know we are being a bit irrational and emotional and in a day or two everything will feel sooo much better we will be fine, so its best not to say anything we might regret while we feel this way....
i dont think men do this so much, (usually i observe you just go down the pub for a pint if you are in a mood, or go down the shed and play with your motorbike or something and are probably best left alone at that point) so maybe it is confusing to you all - but its not a tool, its not a test, we aren't exaggerating our feelings, and yes avoiding it can make you look emotionally clueless, or perhaps just not very good at empathizing- its just what we do when we are having a bad day generally or there is something wrong that we arent sure how to broach, or even if we want to.
What i really want to emphasize tho is that asking 'how are you today you seem a bit not your usual cheery self' (you dont need to go all fluffy bunny on us btw) will not make you appear weak!!
Sometimes girls want to talk about it, in which case let them, dont try to solve their problems, just listen...and other times they dont want to talk, but its still nice you noticed and took the time to ask. If they dont want to talk, sometimes a hug and a cup of tea is good instead