Kissing Gouramis

[Arch]

I have two kissing gouramis and am getting concerned at the amount of time they are fighting now. At the start when you first see them "kissing" its amazing but now they are at it all the time and I'm wondering is it two males i have - its hard to tell with them. Its amazing the way they try to trap the others mouth by quite dirty tactics!! Ones mouth is getting quite red but still they wont stop - is this normal or should i try to stop them?

 

[Doggfather]

Your kissing gourami are fighting. What size is your tank? and how big are they?

The only other time they could kiss is when they breed but they're sexually mature when they're older and bigger.