Are my fish spawnign or getting ready to? please answer must know if i need to seperate rest of fish.?

Question

I have a Tequila Sunrise Guppy and a yellow Tetra that is a little bigger than the guppy, this mornign i woke up to them like attaching there mouths and swimmign in circles, i mean thats what it looks like.

and the tetra keeps swimming to the bottom and the guppy always follows it.

I need to know if i should like seperate them because if they have babies i would like to keep them, and i have 1 Red Tailed Black Shark who is becoming aggresive, 1 BLack Skirt Tetra (not the tetra i was talking about before) 1 Golden Mystery Snail, and 1 Pleco. Should i put plants in because i recently took mine out of the tank.

HELP!!!

lol

Answer 1

Guppies can only mate with other guppies.

Answer 2

Guppies and tetras cannot interbreed.  Guppies are livebearers and tetras are egg layers.  What you are observing is probably aggression.  Many times fish will lock lips when fighting.  An example of this would be when kissing gouramis "kiss."  This kiss is actually two males fighting.