Where do I get the tm sweet scent?

Well, I don't know anything about a TM known as sweet scent but I can tell you some pokemon that learn it through leveling up :

Bulbasaur Lv 25 Ivysaur Lv 29
Oddish Lv 7 Gloom already knows it if caught wild
Bellsprout Lv 30 Weepinbell Lv 33

Oddish learns sweet scent naturally early.

Glooms can learn sweet scent.

Here are all the pokemon that learn sweet scent and what levels they learn it at.

Bulbasaur- learns at level 25.
Ivysaur- learns at level 29.
Oddish- learns at level 7.
Gloom- catch at level 14-17 or re-teach it sweet scent on Two Island.
Bellsprout- learns at level 30.
Weepinbell- learns at level 33.

(transfer the following pokemon from the Ruby and Sapphire versions.)

Illumise- learns at level 5.
Roselia- learns at level 37.
Tropius- learns at level 21.

Bulbasaur learns it.I think Oddish does as well.But it is quite a pointless move in a battle.

Masqaurian..can learn sweet cent.

I'm still looking for the TM in Pokemon soul siver you nut bags.

There are 50 TMs and 8 hms in fire red and leaf green, none of which are sweet scent.