Hey there, welcome to the forum! If that is your fish in your avatar, he's lovely.
To answer your question...
1) He's not kissing you, he's biting you.
Don't worry, it's normal and expected. It might seem like a kiss because bettas' teeth are so small! Try to keep your fingers out of the tank, though, it really isn't great for them.
2) How big is your tank to have all of those fish in there? Also, if it's only been 3 weeks, things can go south FAST. Be prepared to separate all the fish if this is the case.
3) Do NOT introduce another betta with your male. Let me say it again... DO NOT introduce another betta with your betta in an undivided tank!! Males don't need companions, nor will they tolerate other bettas. Females can be kept together in groups of four or more as long as there is adequate space and cover, but you can't put a male betta with any other betta and expect there not to be carnage.
Best of luck to you! If you want another fish, I'd suggest dividing your tank as long as it is large enough.