One who acts in a way, intentionally or not. that somehow eliminates, irritates, or brings attention to someone who is being a wallflower.
A wallmower is often associated with people who are obtuse, socially inept, or cruel - tho sometimes they are acting in this way to eliminate party weeds.
"Was I just wallmowing? Sorry, I have a habit of talking about people loud enough for them too hear, did I say anything mean?"
"Look at this idiot, just sitting there and being all quiet, what's his deal?!" "Hey, stop, you're being a wallmower!"
"I dont think that's a wall flower, I think it's a party weed." "Hold on, I'll go mow him, but back me up if he Hulks out."