gouramis (kissing and otherwise) are territorial fish. kissing gouramis are also exceptionally large for gouramis and will quickly grow to be about 5" long and eventually reach 12" in length!!
i would now like to point out that a standard American 10g is 20" long, 11" inches deep, and 10" wide. this is too small for one adult 12" kissing gouramis. this is too small for one sub-adult 5" kissing gouramis. this is far, FAR too small for two gouramis!
i suggest that you hold off on purchasing any more fish. period. fish get sick when they are too crowded. this will occur to your fish for three reasons. ( 1 ) fish that are territorial and forced into close quarters with a competitor will fight and get stressed out. ( 2 ) chunky fish like gouramis produce a lot more waste than skinny fish like tetras, thus you need more water around them to keep that waste dilluted to safe levels. ( 3 ) high levels of stress, wounds from fighting, and excessive exposure to poisonous chemicals severely weakens a fish's immune system.
if you add any more fish, you will only wind up spending money that could go towards purchasing a 55g on medications, frequent large water changes and probably replacement fish.
don't add any more fish, gouramis or otherwise. you'll be much happier in the long run just saving up for that 55g.
(and just in case, please be aware that their "cute kissing" is actually a sign of aggression. kissing gouramis fight by locking jaws and testing to see who is the stronger. it is also not uncommon for the tankmates of kissing gouramis to lose scales and occasionally even eyeballs if they make the kisser angry. this kissing action is also used to eat surface algae, thus you really have no explicit need for a pleco in their tank unless you just really want one.)
. All it is 2 women with TATTOOS OF FISH. It's really not that big of a deal 
, and if there is further problems I can always join another forum who doesnt worry about a stupid picture and focuses more on the question at hand. 
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